I have no real idea of your aims, or where you are in your fitness journey, but I suggest you start with the exercise you most enjoy. Do you like walking, hiking, cycling, dancing, running? If you start with something you enjoy, you're more likely to stick with it. Once that becomes a habit, you can think about what you actually want to achieve, and why. That will help you decide the best way to get there. Without a map, you don't know if the direction you take is going to get you to your destination.
