Being overweight your best idea is to work on cardio, walk on a tread mill 30+ minutes a day, once you get enough stamina begin jogging. After that interval between both 20 minute jog 20 minute walk, then take it outside the gym or home.
Then once your cardio is strong, and you feel healthy begin lifting and drinking protein/ muscle milk. Even take creatine.
Your fat will become muscle in the matter of months.