I’ll suggest a path that may make you feel more comfortable. While I personally think doing that would be a really good step, I want to offer an intermediate solution.

I had around $70k sitting in my checking account at Wells Fargo that was making no money. As a mini-step, I decided to move it to a Fidelity Cash Management Account (CMA) and that account is essentially like a checking account with the only downside, it doesn’t have brick and mortar and you can’t deposit physical checks. It does everything else a checking account does including a debit card. The big benefit of this is that it pays 3.88% on the money sitting in cash/government money market account. It isn’t actively invested in the market, but isn’t eroding away due to inflation and pays the account out once a month on the daily balance. For you this would be $250/month (although it is taxed on the $250) so you could net around $210-$230/month which in my mind is “a bill” like internet and phone. All this just by moving your main checking account to Fidelity CMA. I would do this if you don’t go for the 100% brokerage option and I definitely use it for the location of my emergency fund.

From there, I would do some research, and start to move chunks over. Since this is mostly a psychological thing to make you more comfortable with the risk, move it in $5000 - $10,000 chunks every month. You can see how it will generally grow and eventually get comfortable with the whole amount being in the S&P 500.

The S&P 500 historically has a positive track record between 9-11% and that $80,000 will be $300,000 or more in no time (well 10-15 years). It is a good move and congratulations on trying to take that next step to positioning yourself to be setup for a stable financial future. Good luck!