Repeating Courses

I currently attend a technical college waiting for the entrance for the lpn program. but while waiting for 3 -6 months i wanted to take some pre-nursing courses.

I attended a community college last year and i did just an average job (1 b engl 101, 3 c's in american gov't, math, and history) (Very hard school). i was going through some very personal problems during this time but hung in there. I'm thinking about transfering to a junior college where seems like a slower pace. i was wondering could i repeat those courses to get a better gpa (at least math) or is it just a waste of time.

I plan to get my BSN at george mason university in va. it is very competitive, therefore, would it be a good idea?