Training before a 12hr shift

I am fairly new to strenght training but i also work in a hospital with long shifts. I generally work in 2-3 day blocks so i plan my workouts arround this, I will workout on work days but usually try to do as few strengh days during working days as possible. I workout every other day most weeks but every other week i pull a 48hr weekend and i wont work out at all.
One big peice of advice i learned the hard way, make sure when you start/increase your workout you have atleast one day off work to recover somewhat. When i first started I worked out monday before work and was ok monday, tuesday however i could barely walk and of course the ER was nuts that night and i spent the whole night running. I wanted to cry. So now when the time comes to up weight/reps I will usually do it on the last day of a block of work days so i have atleast 2 days to recover if nessecary (most of the time one is fine).

If you can pick the days of the week you can go to the gym try different days and see how you feel. It's the only way you will know, give it a few weeks to get your body to adjust then switch.

You should have a good amount of time to rest between strenght workouts. Your muscles will grow while at rest, so at least one day rest between workouts. I only workout 2-3 days a week but when I do I make it count. No way I could go back next day and do it with the same intensity. I think you should start with 3 days or no more than 4 for sure with cardio or some other type of exercise during the other days.