Workout training

Depends on who you ask and what your goal is. There are advocates of whole-body workouts and there are advocates for split training. I would try both and see which responds more favorably given your goals. If you do split, then there are different ways to split - you can either split by body part or split by whether movements are push/pull (not loading too many of the same type together) - this is particularly the case if you focus on 'big movement' exercises rather than more specialized ones.

I’d separate shoulders from arms

depends on your goals. I always said that if I was at the gym during lunch and not eating a cheesesteak, I was already getting an A for the day.

And then sprain your foot, so you have to rest for three months, and cancel your gym membership

You can do triceps and biceps together but not with shoulders.

I believe you should alternate days, I don't but then again I only lift weight's to tone muscles not gain.