In high school start shadowing to be certain this is a path you want to take.
Read the threads listed in this link:
At the same time, study to get a good foundation in all of your classes so you are more likely to do well in your college classes. A bonus for doing the studying should be a nice GPA to help get into college - perhaps with good aid. Be sure to prep for the SAT/ACT as usually you will need a decent score on one of those too.
In college pick any major you like and do VERY well in it. Register with your Pre-Med (sometimes called Pre-Health) department to get their input and guidance but be super aware that there are Pre-Med departments out there that DON’T give good guidance to their students, so keep abreast on this sub-forum too:
http://talk.collegeconfidential.com/pre-med-topics/
You will also need some decent ECs. Here’s what one med school likes to see in their successful applicants. You can change the year in the URL to see it’s a template. I suspect pretty much all other med schools are similar, so read over a few years and see what sort of things that interest you that would fit into their description while also doing the things “we’ve come to expect in medical school applicants.”
https://www.urmc.rochester.edu/MediaLibraries/URMCMedia/education/md/documents/2021-profile.pdf
As you go through college, decide which year you want to apply - many students take gap years between college and med school. Take the MCAT after preparing well for it. Get recommendation letters. Fill out your application and submit it pretty much as early as possible as earlier apps get more consideration. (This is one area where Pre-Med departments can give wrong info.)
One can get far more detailed of course. There are also DO schools (but look at those carefully as MD and DO graduates will compete in the near future) and Caribbean med schools (ditto with looking at those carefully). There are post bac programs and BS/MD programs. The links above contain a wealth of knowledge to where a summary should suffice for the “basics.”