The pain in the leg before workouts may be due to some amount of arthritis. So it is always good to go for an orthoapedician and find about the anatomy of the knees.
If everything is perfect you can go to a trainer and try anytype of weight losing cardio.
But with problems it is always good to select what would be good to you. At you age we do not suspect and problem and also go to a dietician for a proper diet chart. Balanced diet and exercise should go hand in hand. Take care!
Hi again,
Sorry I just read the P.S. to your previous post. You are right, more than likely your pain will go away with some weight loss, but if your insurance is good it would never hurt to get checked out by a dr. or a physical therapist. Just make sure that you are not doing any high impact activity for the time being (like anything involving jumping), as it will put more stress on joints that are already stressed. For now try to stick to lower impact activity (especially when doing cardio) like cycling, elliptical, walking, swimming, etc.
Again congrats on your initiative :) keep up the good work!