I am a freshman in high school
Most people don't take these tests until Junior year. Keep them in mind as things that you'll do in the future, but you should really be focusing more on extracurricular activities and your coursework. The earliest I think you should study for it is the end of your sophomore year but I wouldn't take it until the middle of your junior year.
I think it would be best to focus on your classes during your freshman year, and you could begin shifting your focus to the ACT/SAT during your sophomore year. Taking the PSAT your sophomore year would be an excellent way to see what skills you need to improve on before taking the SAT.
To keep this community safe and supportive:
you can take the PSAT as a benchmark and maybe get scholarship money but do not worry about it focus on coursework and ECS but try to focus on stuff relating to what field you want to go into like medical business etc