Practice the front roll and the back roll first, and slowly practice the roll with your head close to the ground but not touching the ground. Push-ups are the best choice after practicing arm strength. Don't do too much in a day, but stick to it. Daily suggestion 10~ 15. Then use arm strength to prop up the body and turn the rollover into a somersault. It is important to pay attention to arm strength. Or you can sign up for a martial arts class, such as Jeet Kune Do. I hope it will be adopted and wish you success.