"what box do i check if i made out of state taxed pruchases?"
If you're deducting state sales taxes on your federal return, then you check the box on Line 5a of your Schedule A.
https://www.irs.gov/pub/irs-pdf/f1040sa.pdf
Your federal return does not ask about in-state vs out-of-state purchases.
Your home state may charge a "use tax" if you bought items out of state and paid no sales tax on them. Since you say you did pay sales tax on your out-of-state purchases, you probably owe no use tax. However, if the sales tax rate you paid in the non-resident state is lower than your home state's sales tax rate, some states may charge a use tax on the difference.
In order to tell you what boxes (if any) might need to be checked on your state tax return, we'd have to know the name of your resident state.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
