What to expect from JROTC?

It is my freshman year and I picked JROTC. In the begining I was excited. But now that I know more about it, I am rethinking my choice. (Even though I won't be able to switch to another cl.) Tropical Storm Fay has taken away 2 school days (Yay!!) and now I am wondering more what I got myself into. What is it like? What do they do?