Simple bodyweight stuff inside your own home for muscular fitness, if you're not confident exercising in public, try walking up your stairs loads of times. If you are confident exercising in public, walk up a steep hill. I wouldn't advise running yet as your muscles, tendons and whatnot will not be used to the impact. I also wouldn't advise doing weights at the beginning, it can be intimidating sharing space with a jacked body builder and you can unknowingly incorrectly do an exercise and severely injure yourself. I am currently training for the parachute regiment in the army, so my fitness regime is more about endurance, cardiovascular fitness and power, rather than being huge, so I might be able to help you out a bit more than others on this forum.