How many times can you retake the ACT and SAT test in 12th grade ?

Have you done any test prep? Not worth your time if you have not studied and prepped. If you are applying for colleges for Fall 2019, you probably only have 2-3 more sittings depending on the test dates and the college deadlines.

http://www.act.org/content/act/en/products-and-services/the-act/registration.html

https://collegereadiness.collegeboard.org/sat/register/dates-deadlines