Can you tell me how to measure how much of muscle mass i have?

Calipers are best.: This is hard in this small space. You measure your fat mass and your weight and calculate your lean mass. Hard to isolate muscle alone from other non-fatty things like bone. Hydrostatic weighing in a tank of water is the most accurate but inconvenient and expensive. Calipers give results closest to hydrostatic weighing but bioimpedance devices give decent estimates. Trainers in a gym can help.