What exercises can i do to just tighten and slim my body

what exercises can I do to just tighten and slim my body and still keep my booty?

You need to mix cardio and weights. To tighten up you need to gain muscle and loose fat. Exercising a certain area alone will not make you loose fat in that area. To loose fat you need to burn calories and the best way to do that is cardio. However, I would suggest not being afraid to spend almost equal time on weights. Too many girls think that they will get muscular if they do just a set of curls. Especially if you want to keep your curves, you'll want to pay attention to squats, lunges, leg curls, etc.