I would suggest starting out with push ups and inverted rows for upper body, especially if you are a big guy. It’s been awhile and you definitely want to ease in that elbow and shoulder. If you feel fine with it, you can also start on the bridge progressions, although I’m not sure how it will do for your shoulder.
Lower body…generally of course I would recommend getting really comfortable with squats and lunges, then start working on shrimp squats or pistol squats. The thing is, since you have a history of working out yet need to ease in the upper body, I am thinking that, until your shoulder and elbow can be relied upon more heavily, you will need to get the bulk of your actual work done with lower body. Jump rope is a great place to start, swimming is excellent too. You could get a lot of conditioning in that way, and either one should help build up stability in the shoulder, as long as they don’t aggravate it.