Try a three-tiered approach to exercise: power yoga for flexibility, stamina and core strength; bodyweight exercises and plyometrics for power and speed; running for endurance.
Here’s a quick workout you can use; do each exercise, one after the other without rest, as a series; repeat the series twice:
Do as many as you can. You’ll have to work up to doing even one. Keep at it. It took me three years, but I can now do ten wide-grip chin-ups with strict form.
As many as you can. Again, you’ll likely have to work up to it, but aim for a total of twenty. Eventually, you can start doing them with your feet up non a bench.
Do twenty-five, jumping as high as you can. Once you can do the twenty-five with ease, do them holding light dumbbells.