Should I Join the IDF Before or After College?

I am really interested in joining the IDF. I am almost 16, live in the USA, but next year I will live in Israel. My Hebrew is barely enough to get by, but I think when I live in Israel, it will get a lot better. I get pretty good grades, so its not like I want to choose the army because I don't have good grades and I could get into many UCs. So what should I do? Join the IDF before or after college?