Here is where you should start to learn about the GMAT, and how to study:
gmat-study-plan-start-your-gmat-journey-80727.htmlIt is not recommended that you start studying 2 years before you take the test. It is generally recommended that you start about 3 months out, and study hard for those 3 months. It is hard to keep motivation over 2 full years. It might be more important for you to concentrate on other areas while you're in school to help you application in the future.
You should try to get good grades, good experiece especially with jobs and internships, and good leadership experience in clubs or organizations while in school. Business Schools are going to want to see a person that is very well rounded in all areas, not just the GMAT. A good GMAT score is also important, but the scores only last for 5 years, and the test is continually changing. So it may be good to familiarize yourself with the test, but take it closer to when you graduate college.
Also, if english is your second language, now may be a good time to pick up a reading habit, and start reading books in english. This work you put in now will greatly help your verbal portion of the GMAT in the future. Feel free to come by and ask us any questions on your journey!
PS. US business schools have really put a large emphasis on work experience. The job you get out of college will most likely be one of the most important factors in helping you get into a top business school. It is typical that someone will get 2-7 years of work experience after college, before applying for their MBA.