Do well in your junior and senior years of high school, try and challenge yourself with honors/AP coursework without sacrificing too much GPA points, do well on the SATs, volunteer, try and get some leadership positions in school clubs, make sure you apply to college early with a solid application, and prepare for your interviews. Once you get to college, party hard yes, but pick a good solid major that can prepare you for whatever career you find interesting, and be sure to make use of whatever resources you have such as pre-professional advising, and try and take a variety of courses not just in the sciences but in the humanities as well, since pre-collegiate, public schooling in the USA is an affront to the very definition of "education".
Also, have fun in BJJ.