39% body fat is high!!! You're in need of a good diet! Once you clean up your diet you can try something like a cutting cycle but first, everything starts with a solid diet, training and then anabolics, if you choose to take this route. Not the other way around. I have clients who are out of shape, like you, and come to me with the idea that I can perform miracles...and like you want to go on gear right away. I personally don't feel that you would make solid gains on Prop or anything else, until you learn to eat properly and are able to follow a diet consistently, not just for a day or a week. I've lost many clients this way but this is the correct way of going about doing this right. At 50 years old, you have no room for mistakes! If you choose to use gear with your body fat the way it is, you will only make things worse. You won't be able to decrease your body fat and get in the shape you're looking for.