How to get in shape for track?

I'm planning on joining track next semester in August. So I have over or about half a year to get ready, which I hope is enough. I'm not athletic at all, and I have no experience in athletics or sports either. The only things I've been doing is doing push-ups everyday since maybe a little around 2 weeks ago. I do around 100-400 in a period of 30 minutes (not all at once, and obviously not that much for 30 minutes.) The most I've done at once with out stopping is only 110...and that was a first. The average I can do for each set is around 60-70. What else should I do to get ready for track? Besides running...I need to get my body in shape first. I think.