@perspicacious says “It’s not quite that competitive now.” I disagree. The circumstances might be different, but I would say medical school is even more competitive now. Due to the recession, lots of people have realized the need to be in a career with more security. Application rates have risen up and medical schools have been stricter and choosier.
That said, high school is not the end all. Finish up high school with the best gpa possible, you might have to go to a less impressive college, but as long as you kick ass there and do amazing on your MCATs, you should be fine. All of this requires the utmost hardwork, dedication and motivation, so be sure you’re up to the goal. If you like biology stuff, do a related major in college and then by your junior year in college, you’ll know whether you like it enough to pursue medicine, or while taking other courses in college you might find another career you love much more. Bottom line – you have time, don’t set yourself for one career quite yet, keep an open mind, do good in whatever you study.