I’m starting freshman year in September and I want to take the medical route. I know that foreign language is useful in this field but, I’d like to try other things in high school like CompSci. I already have 2 credits in Spanish btw. Thanks! 
I would advise taking 3 years of a foreign language because you would have met the requirements for most colleges. If you are coming to high school with 2 Spanish credits already, I think you should maybe take 2 more like Spanish 3 and Spanish 4 or AP Spanish (whichever one you feel more comfortable with taking/allowed to take). Definitely take Spanish 3, though because you don’t want to end up applying to college and realize that you don’t have enough foreign language credits for your desired college
You will have to meet foreign language requirements to get into college AND foreign language requirements to graduate from college. All in all, the more you can take in high school, the better off you are when you take the placement test in college and the fewer classes you have to take in college.
Taking Spanish up to AP would probably meet the foreign language requirement at the college too, unless you’re aiming for a college like Yale or Tufts.
Being premed in college means
1° choosing ANY major you can be top 10% in
AND
2° ranking top 10-20% in each pre-req you take - ie., when you take the Biology sequence you have to be better than 90% students, in the Physics sequence you compete against future physics majors, etc.
The pre-reqs are needed to take the MCAT and to apply to med school. Not all med schools have the same exact pre reqs but you cover all your bases if you have:
2 semesters each of Biology, inorganic chemistry, organic chemistry, physics, English (writing, communication, literature); one semester each of calculus, statistics or biostatistics, biochemistry, neuroscience, psychology, sociology; it’s very helpful to have a diversity-focused class and knowledge of a language spoken by an immigrant group, although that can be learned informally through community education or a clinic (Hmong, Kreyol, Korean… all count).
Your college classes aren’t “medical” in any way, unless you attend a college that offers a Medical Humanities major where you can take History of Medicine, Medical Ethics, etc.
Also, please note that contrary to popular belief, your required classes include more chemistry than biology (5 vs. 2).