Study the 1040 TurboTax gives you, and next year try Free File Fillable Forms! You have to select which forms, but FFFF does a lot of the math for you. Things get a little complex if you have capital gains, but if you're motivated by spite like me, you can figure it out. www.irs.gov/e-file-provi...
You also have to do your state taxes yourself, which can be a drag. And full disclosure, I did mess up my taxes the first time I used FFFF. Fortunately it was an error in my favor, though, and eventually I got more money back.
"motivated by spite" 😆
It happens to work for so many annoying tasks!