The general answer is that astronomy is an applied branch of physics, and that means you need a lot of math. If you are just taking an astronomy undergrad as second major, you can probably get out with just a few semesters of calculus, and possibly differential equations. read more
If you mean you are not good with math, from what I have heard of astronomy is a lot, and a lot of math. So you have to be decent at it and know all of it. Think about it. Astronomy is pretty much math. read more
Of course you do not need a college degree in Astrophysics or Astronomy to look at the stars. Until that big college graduation day I recommend going with a group of friends to a large clearing and letting your imagination do the rest. read more