Being in ROTC and army reserves at the same time?

in order for my scholarship to work I have to be in ROTC at my college and army reserves simultaneously. What kind of things does a cadet do in reserves? Also, they gave me the option of doing reserves OR national guard. what would be the pros & cons of each? I'm really leaning towards reserve because I feel like national guard is more state military where as reserves are still more national control. also, with reserves i'd like to switch to active duty at some point. can you do that with national guard?