you can do exercises to build muscle if you want that, if you want to stay thin you could just do light exercise to stay healthy, or get a bit toned. cardio might be a good start for you.
Actually, I ain't thin; I am a chubby lady. As I try to think on what exercises should I need to perform, I guess I'll do planks, setups, push ups and perhaps some cardio but doesn't require much of jumping.
First of all, I don't think you should exercise to change your body. Second, if you want to build muscle it's the best for you if you do compound excersice, the most effective one you can do at home without any equipment is a push-up. I hope this helps!! I don't know who you are but know that you're loved <3