exercise is great but without fixing your diet it won't do enough
also adequate amounts of sleep as this is the time your body is trying to repair all the damage you do to it.
and the final one which sadly I struggle with is STRESS. we live in an overly stressed world and i hate that.. but you have to manage it best way you can
ANYTHING that gets your heart rate up and gets you moving is great. Get creative so you don't get bored. You could go swimming, go for a bike outside, take up dance lessons etc.
I would vary your exercise and definitely focus on the diet. Those 2 combined are what is going to really improve the issue. Either one on its own is good but you really want both.