Compound movement is an exercise which involves several muscle groups at a time. For example Bench Press, Deadlift, Squat, Military Press, Rows, Pullups, Dips, lunges, ect. The more muscle groups you use the more effective your workout is gonna be, you will also burn more calories. Overall by doing some HIIT along with a solid weightlifting routine I think you can reach your goals a lot quicker. If you want I could write you up a fairly basic routine to get you started.