Legs are just as important for strength as the upper body is. So you want too build strong legs. If you plan on using a gym or equipment than the most basic exercise too know is the squat.
You can do hack squats on a machine or you can use a barbell. Try doing medium weight, enough weight so you can get out 10-12 reps. After that move on too a leg press and again weight so you can do 10-12 reps.
After that do leg extensions and 10-12 reps and than do a leg curl for the hamstrings and again 10-12 reps. For sets, do 3-4 sets each. This might be for people who are more advance so if you are just starting out, than just cut down on the sets and do only 2 sets of each of the exercises listed.
Also you can try and walk a lot and jog or run a few times a week. If you get bored with these exercises, than switch it up but always leave a squat exercise in your leg routine. Squats in many opinions are the most important exercise you can do for your legs. Like always, get clearance from a professional or a doctor before you start a routine or regime.
