Each college and university has the information about foreign secondary school records right on its website. If you can’t find it easily, check the page for international applicants.
You also need to verify the correct steps with the admissions offices. Tell them that you are a US applicant who was educated abroad. There are many students like you! The admissions offices will be able to tell you what you need to do. Don’t worry if each college tells you something a little bit different. That is OK. Just do whatever College A asks for College A, and whatever College B asks for College B.