Research the ap/de/clep policy of several colleges but don’t forget to look at the program requirements of the major too! It’s doesn’t do much to rack up a bunch of college credits if those credits can be applied to the major course requirements.
Understanding college policy can also save you some money, for instance by 12th grade my daughter knew she was going to OU, for English requirements they will give credit for BOTH required English classes if you get a 5 on either AP English or AP Lit, since she got a 5 on her 11th grade English AP she didn’t bother taking the her 12 grade AP English exam and that was one less test fee I had to pay the College Board! My youngest is very likely going to UTD and since I know they don’t give credit for AP World History he won’t be taking that exam either.