You do have some time to go, but it is always good to have a game plan early on.
Here are two really good resources that will help you:
The short version of these is that there are several paths to being an airline pilot, if your goal is flying for the majors, then your path needs to involve college. I personally recommend four years of college, then flight training. Your degree can really be in anything that you wish, as long as it is from a reputable school.
Take a look at those links and the FAQ section, there is some great information there. Let us know if we can help further clarify any of that.