i want to be a physicians assistant, but don't no what major to choose?

Start from the top and work backward. Look up the admission requirements for 3 or 4 PA programs to which you might want to apply. Based on that information, decide whether or not you can complete all the prerequisites while completing a non-science major as well. If so, pick whatever major you want. If not, then accept that you'll need to do biology or chemistry as a major.

Most universities has pre-med advisors who can help you chart your course selection based on your goal of getting into PA school and your potential major. Since you don't need to select a major until the end of your sophomore year, you don't have to decide immediately anyway.

Here's a suggestion; don't aim for being a physicians assistant, aim for being a physician. Why limit yourself to assistant? And that way, even if you don't manage to finish medical school for whatever reason, you'll STILL be qualified to become a medical assistant if you still want to be one.