Second what A-Rod said, more or less.
A physical therapy regimen is essential, and you need to get your doc to refer you to a good one or find one on your own.
Second priority is getting ROM back. I am not an expert on this sort of thing so please take with a grain of salt, but it may be possible for you to get most of the rang of motion back from before the wreck. Regardless, what I DO know is that the longer something stays stiff and immobile the worse and more ingrained the bad compensation patterns become, so ROM is absolutely imperative for the long term goal of a balanced motor pattern and strength (pain-free goal, of course, and with a specialist).
After ROM generally is endurance, and to a large degree both of these things overlap.
As far as legs go train them with as much intensity as you can without aggravating pain in your shoulder. Whatever variations you can get pain free, do them. If back squats hurt but front squats don’t, front squat. If both hurt but the Safety Squat bar doesn’t hurt, do SSB squats. If deadlifts don’t hurt, do them. If kb swings don’t hurt, do them. Same with exercises for the back and exercises for your chest/tris.
Again, I am not an expert but my suggestion–please confirm it with a specialist who knows athletes not grandmas–is to avoid benching (obviously you are not overhead pressing right now lol). Most of my training for the chest and triceps would be isolation right now unfortunately, because it will put less strain on your shoulder while you get ROM back. It will still help a lot, and will help avoid compensation patterns from struggling with technique on bench. Shoulders…I dunno. anything that doesn’t hurt. Pay special attention to the supporting musculature from here on out (rear delts, rotator cuff, rhomboids, and serratus). The more fully developed all of the supporting/postural/rehab muscles are the less stress is placed on the ball joint and the more “diffuse” the strain during any exercise–more muscles to spread the workload around.
IMVHO this means that your medium term shoulder training plan is to permanently shift focus to making sure your shoulder is super quadruple bullet proof in all the small ignored muscles. Not only that, but make them legitimately STRONG (they’re hard to focus on, so you have to be super strict with tempo and form generally speaking. Eric Cressey showed the difference in tempo on a rehab exercise leads to a difference in muscle activation of various stabilizers, with slow being better. When you rush you get compensation patterns). You will forever be more susceptible to imbalances in the postural and stabilizer muscles. That, however, does not mean you can’t eventually get strong. Just you gotta be careful.