Simple and direct shots are best for beginners. Avoid clutter, which will take away attention from your subject. Fill up the viewfinder with your subject. To get a more natural expression from the subject, tell them it is not necessary to flex their hardest. A moderate flex will often give more flattering expressions.
Film is the cheapest part of photography.
Edit out the pictures you don't like. Don't expect professional-looking results the first time. Start an album. By keeping your pictures in one place you can keep track of your progress in both bodybuilding and photography. Find a good color lab in your area, and take your film to them to get processed instead of the drugstore.