hi Cailin,
Basically there are simple but time taking steps.
1- Credential Evaluation of your education in physical therapy (for each stat it differs, so better to start with those who has minimum requirement like NY or michigan)
2- When you get your credential report, and if there is no deficiency then you should apply with health board of that state, and they will send a letter to FSBPT (central authority to conduct and regulate physiotherapy exams).
3- when health borad of your respective state sends your eligibility of test, than you should apply for Approval for Test from FSBPT.
4- Once you got a letter from FSBPT, than you have to call the prometric test centres and book for test within 2 months.
5- Go to USA. appear in exam and if you pass then you will be liecnesed to work.
6- After that you can start looking for employer and proceed with visa work.
Best of Luck