Motivation, motivation, motivation.
Fast walk a couple miles everyday, and then gradually lean into running/jogging. This does wonders for your legs/buttox/waist area - and you're not taking it too fast. I've lost a lot of weight just by doing this!
Also, diet wise, water, and watch the carbs.
If you want an intense workout, my brother just graduated from Marine Corps boot camp, and some things they did was Mountain climbers, sit ups at a slope, and run a lot. He gained about 20 pounds in muscle! Although, I think it could work for you in the weight loss department, as well. I plan on joining the military when I turn 18 - so I'm getting ready for it now.
But, you have to motivate yourself. If you walk/run a couple miles for 2 days, and then quit after that, you're not moving along the process. Always remember to do a cool-down exercise and you should be fine. Really, a lot of people tend to overthink weight loss - even the little things help in the long run!
PS: Try hot compresses for your leg.