Playing football once i a week won't affect you bad at all. Neither walking a lot.
If you really want to grow your legs you should consider doing a proper training. Spartan Bows can be a good excersice but it won't give you bigger quads just by itself.
The best way is at the gym but if you can't go to the gym or you don't want, you can train at home. A good workout program for legs would be something like this:
- Body Squat
- Lunges
- Step Up
- One Leg Squat
- Jump Squat
You can add dumbbells if you want to get higher volume. That would be a good workout to start working your leg muscles and add some mobility. You can do this one in a week or two if you change some of the excersices the second time. Don't expect to see enormous growth but keep training on a regular basis with a proper nutrition will give you the result you want.
Also, excellent excersice for max quad growth is bicycle and all the variants. Especially trainining in incline will burn your quads.