How do you enter a 1099SA as a hobbyist musician and part of a band? Is that considered self employed?

Income reported on Form 1099SA is not self-employed income.

Forms SSA-1099, SSA-1099-SM, and SSA-1099-R-OP1 report retirement, disability, and survivor benefits from the Social Security Administration (SSA).

Don't confuse the SSA-1099 with the 1099-R that reports retirement benefits from non-SSA sources like pensions, 401(k)s, and IRAs. 1099-Rs are entered elsewhere in TurboTax.

All SSA-1099 forms get entered in the same place:

1. Open (continue) your return in TurboTax, if it's not already open
2. In the search bar, search for the term Social Security benefits and then select the Jump to link at the top of your search results
3. On the screen Did you receive Social Security or Railroad Retirement benefits in 2021? answer Yes and select Continue
4. On the next screen, check the box beside Social Security benefits (Form SSA-1099), then enter the amounts from your form(s) in the boxes provided
   • If you received multiple SSA-1099s, add up the amounts for each box and enter them together
   • Don't include SSA-1099s for dependents. Those should be reported on the dependent's return, but only if they are required to file a return (this is uncommon)
5. Select Continue and follow the on-screen instructions

Thie TurboTax link https://Where do I enter an SSA-1099, SSA-1099-SM, or SSA-1099-R-OP1? has information you may find helpful.