I sold RSU stock last year, two different grants: 2020 and 2021. My brokerage account doesn't have the info from either date. Thoughts on what to enter into turbo tax?

You can enter the Form 1099-B information as a regular sale of stock, you don't need to indicate that it is from a stock purchase plan to simplify things.

The income you recognized in the year the stocks vested would likely be your cost basis for the securities, provided you didn't pay anything for them. That income would have been reported on your W-2 form. So, look on your W-2 form and find the vesting income and enter that for the cost basis of the RSU investment sales listed on your Form 1099-B. There should be an amount listed in box 14 for the income. If you paid anything for the stocks, add that to the income reported on the W-2. For the dates acquired just make sure you pick a date that will result in a long-term (held one year or more) or short term (held less that one year) holding period.