bro, if you are seriously thinking abt losing weight, dont get into this body building thing..
what you ca do is to do some atheletic type activity, ( much more healthier for your body, than body building)
top ways to reduce weight are
Jogging, remember long distance runners lose weight quickly than sprinters
Swimming, 1 of the best exercises, remeber to focus on long distances than speed.
cycling, same rules apply
Hiking, is one of the best methods too
Skipping ropes