Unfortunately, there is no answer to your question because there is no standard physical therapy treatment for anything. Every physical therapy clinic is a business, and how it's run is dependent on whoever created the business. Some have their own theories. Some let their physical therapists determine the treatment. Most will keep you as long as your insurance holds out; when they think it's getting near the time the insurance company will stop paying, they will stop treatment and discharge you. If you get better, they will stop treatment. If you still hurt, they will continue treatment. If your prescribing doctor severely limits your number of sessions, that's all the sessions they will do. If he keeps renewing the therapy, they will keep doing treatment. There are thousands of different exercises physical therapists know, and they will keep adding them if you don't report improvement. The best way to set a limit is to get better, but we're not always that lucky. I've been in PT several times, and so has my wife, and so we have learned the ropes, so to speak.
This is really dependent on the injury and extent of repair. A labrum may be different than a rotator cuff, and each will be different depending on the injury and type of tear, etc.
I had a torn labrum - a SLAP tear - and I needed repairs to the bicep tendon, some scar tissue cleaned out. It sucked. I was immobile for several weeks - I think 6? maybe? - then went to PT. PT is hell. It's been several years, so I don't remember how long I was in PT exactly, but I'd say at least 12, twice a week. It may have been longer - maybe 16 weeks?
Certain parts of PT were worse than others, so I can't say there were time frames that were better than others. I had to do this exercise where I had to sort of climb my hand up a wall to stretch the shoulder, and then hold it in a stretch. The length of time in the stretch extended the longer I was in PT, but every single time I did that, I hated it. Other exercises that were just for strengthening weren't nearly as bad. Plus, they did a mini-massage and stim thing at the end, which I loved, followed by ice, which I hated. Some of that will be personal likes and dislikes.
Prior to the surgery, I couldn't reach in certain ways, like I couldn't get something off a higher shelf, couldn't put my hair up, couldn't reach around to unhook my bra. Certain things were definitely a ""damned near tore my shoulder off" prior to surgery - it's how I knew I had an issue in the first place.
Immediately following surgery, everything was a "damned near tore my shoulder off". I've had a lot of surgeries - ankle reconstruction, a hysterectomy, a few others, and while the ankle had the most pain immediately after, the shoulder was definitely the worst recovery. It got better, and then when I started PT, it was back to that, and then only some exercises were that bad. It wasn't until the last few weeks of PT that it may have been an "they gave it a trim to get rid of the split ends" appt.
You won't be on pain meds the whole time. They'll give you anti-inflammatories, and watch those. Check the warnings on them. They can give you bleeding ulcers. Ice will help a LOT.
I've talked to others who've had shoulder surgery, mostly labrums, though some rotator cuffs and a separation, and they all agree that it sucks.
There is no standard for this. It depends on you, a lot, and how well you do your exercises.