I need some advice on a photography portfolio for college. Needs help!?

At this point do not rush to fill in any gaps. Put 10 of the very best images in the book and hope for the best. Frankly, most beginners are very heavy on one theme-so you're not alone. Just concentrate on putting in the very best images you have, make sure the pages are spotlessly clean if you are using a print portfolio. Then go out and start shooting a wider variety of photos.