Physical Therapy. The surgeon who performed you ankle surgery can refer you for physical therapy. This will help build up your muscles as well as help with mobility and range of motion of your ankle.
Several things. You want to do range of motion exercises along with stretching. You may also want to start doing leg curls and increasing the weight as you feel comfortable.
PT. You should have been referred to physical therapy for rehabilitation.
Don't. You could injure your ankle and disrupt your surgery by working out.