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I would want to know what you mean by "fully funded emergency fund." Home equity is very non-liquid. How stable is your income? Do you have disability insurance? How much life insurance do you have? Do you have portable life insurance policies outside employment? How many years are left on the mortgage with minimum payments? Are you single income household or are both spouses working?
With a young child, house, and big mortgage, I would feel more comfortable with 12 months of living expenses plus 12 months of COBRA premiums. Things like job loss, lumpy home maintenance expenses (e.g. new HVAC, roof), car replacement/maintenance, major medical, criminal cases (e.g. bail money, lawyer), or other lumpy expenses can pop up. I also like having a car replacement fund in liquid cash outside my emergency fund.
I would review your life insurance and disability insurance coverage. Death and disability can happen. Consider creating or reviewing your estate plan. Perhaps spending $100 per month on life insurance on a portable 20-year term life policy for both spouses of $2M each, and spending $2k on an estate plan creating a trust, wills, and POAs could be money well spent rather than putting everything in non-liquid like home equity or putting more in 401k.
A mortgage of 6.125% is around 8% after taxes at your income level, which beats any fixed income asset. That is like getting a guaranteed 8% return.
If you truly have a "fully funded emergency fund" with 12 months of living expenses, with adequate insurance coverage, and an estate plan, I would probably put the extra $1k in extra mortgage payments after investing 15% in retirement contributions and 529 contributions. Alternatively, you could split the difference putting $500 toward the mortgage and $500 toward 401k contributions. It depends on your risk tolerance. Either way is good.
You might mix in some traditional 401k rather than 100% Roth 401k at your income levels. Do you expect your incomes to increase? You are currently at a 22% marginal tax rate with $185k MFJ. I would probably go 50% traditional 401k and 50% Roth 401k, and then fully fund Roth IRA ($7,500 x 2). Having a mix of different tax buckets is optimal because you don't know what future tax rates or income will be, especially in your 30s. If you ever do QCDs after age 70.5, then having some traditional is also helpful.

I would want to know what you mean by "fully funded emergency fund." Home equity is very non-liquid. How stable is your income? Do you have disability insurance? How much life insurance do you have? Do you have portable life insurance policies outside employment? How many years are left on the mortgage with minimum payments? Are you single income household or are both spouses working?
With a young child, house, and big mortgage, I would feel more comfortable with 12 months of living expenses plus 12 months of COBRA premiums. Things like job loss, lumpy home maintenance expenses (e.g. new HVAC, roof), car replacement/maintenance, major medical, criminal cases (e.g. bail money, lawyer), or other lumpy expenses can pop up. I also like having a car replacement fund in liquid cash outside my emergency fund.
I would review your life insurance and disability insurance coverage. Death and disability can happen. Consider creating or reviewing your estate plan. Perhaps spending $100 per month on life insurance on a portable 20-year term life policy for both spouses of $2M each, and spending $2k on an estate plan creating a trust, wills, and POAs could be money well spent rather than putting everything in non-liquid like home equity or putting more in 401k.
A mortgage of 6.125% is around 8% after taxes at your income level, which beats any fixed income asset. That is like getting a guaranteed 8% return.
If you truly have a "fully funded emergency fund" with 12 months of living expenses, with adequate insurance coverage, and an estate plan, I would probably put the extra $1k in extra mortgage payments after investing 15% in retirement contributions and 529 contributions. Alternatively, you could split the difference putting $500 toward the mortgage and $500 toward 401k contributions. It depends on your risk tolerance. Either way is good.
You might mix in some traditional 401k rather than 100% Roth 401k at your income levels. Do you expect your incomes to increase? You are currently at a 22% marginal tax rate with $185k MFJ. I would probably go 50% traditional 401k and 50% Roth 401k, and then fully fund Roth IRA ($7,500 x 2). Having a mix of different tax buckets is optimal because you don't know what future tax rates or income will be, especially in your 30s. If you ever do QCDs after age 70.5, then having some traditional is also helpful.

Using my Claude code 50x supreme intelligence to watch all the vintage porn movies and categorize them by tittie torpedoness from a scale of Hunt for red October to Ball Sag on an August afternoon in Alabama when the HVAC is out because a raccoon are into the refrigerant line again.

Nice I'm positioned well as an HVAC technician 

I've been considering investing in FIPFX 100% for my Roth IRA. Is this a good choice? I don't love bonds in Roth IRA and FIPFX is a target date with bonds. Roth IRA space is precious and it's best to use Roth IRA space for 100% equities/stocks and no bonds. You can also do VTI, VT. If you have Fidelity, zero funds like FZROX and FNILX are also good.
Now that I have a Roth IRA, is it better to make my 401k 100% traditional? I would probably go traditional 401k (not Roth 401k) but max out Roth IRA for both spouses. You are probably at a 22% federal marginal tax bracket as MFJ with household gross income of $172k.
Is it more important to max out my 401k first before opening a brokerage account? Yes. Standard recommendation is to max out tax-advantaged space like 401k and Roth IRA before a taxable brokerage.
If I open a brokerage account, how much to divert there? I would keep around 6-12 of living expenses as an emergency fund, plus buckets for future anticipated home repairs, and car purchase. Let's say a new HVAC system is $15k and car replacement is $25k. That is around $40k total. You could keep $60k in your emergency fund and $40k for the HVAC/car fund. You could put the other $190k in the market. You could lump sum, or dollar cost average over the next 6 months ($32k per month) or 12 months ($15k per month). You could set aside $15k for Roth IRA for January 2027 for both spouses. You can max out Roth IRA on January 1, 2027 for both spouses ($7,500 x 2).
Are there other types of accounts I should consider? Spouse should also max out Roth IRA. Spouse can also contribute to 401k or other similar plan if available through employer. If spouse is self-employed, spouse can open a simple IRA, SEP IRA, or solo 401k. You can look into HSA during open enrollment, but only if it makes sense in your sitaution.
Note: With a mortgage of 5.5%, you could put some of your $290k in cash in principal mortgage payments. That's like getting a guaranteed 6-7% after taxes. You could also split the difference such as: (1) keep $100k for emergency fund/HVAC/car purchase; (2) invest $100k in the stock market in spouse's Roth IRA and taxable brokerage; (3) pu $90k in extra mortgage payments.
You are doing really good. With $477k in current retirement savings (keeping $100k for emergency fund/car/HVAC), if you contribute 15% of your $172k household income ($26k per year) for 25 years, with a 6% real return, you could have around $3.5 million in current dollars at age 65. With a 4.5% withdraw rate, that could be around $157k in current dollars that would replace nearly 100% of your current household income for both spouses, plus no mortgage at some point and any Social Security.
If you max out 401k for both spouses and get your taxable income under $100k as MFJ, you could have some space in the future for 0% long-term capital gains within a taxable brokerage.

Anything tied to needs rather than wants. Plumbing, HVAC repair, pest control, funeral services, debt collection, and discount groceries tend to hold up well. Repair businesses often grow during downturns because people fix things instead of replacing them. No business is fully recession-proof, though. Low overhead and steady cash flow matter as much as the industry.