What do I need to know about my new guinea pig?

i dont think you ever will, i think every guinea pig is like that well all mine have been, whenever you go over to the cage door there running everywere and when you try to get them out the same thing, but when you get them in your hands they calm down and liked to be stroked. but i dont think your ever going to stop it bein jumpy. it should be alright with that food until you can get some proper guinea pig food, try feed it some carrots or cabbage, brocolli. but it should be fine with rabbit food it wil leave the bits he doesnt want