@bellae2156 , My daughter's nickname is Bella! It's a good idea to start with PT to get good form! There are therapists who specialize in OP, so see if you can find one.

I have been lifting weight (dumbbells and machines) on and off since I was like 12 (for sports) so I am very comfortable doing it on my own. My last stint of daily lifting (5 days/wk) was 2014-2024, until I retired in 2024, and started at a new gym, where I continued. Unfortunately, all the ten years I was eating too little protein (only 30-40 grams a day), so I didn't get the full effect of the exercise. I also didn't separate my calcium and magnesium, so not good absorption there! And my estrogen was very low, and so here I am.

I do legs on TU TH, and arms on Wed, and abs/core, balance, and leg slams on all three days. Each session starts with 45 mins on treadmill, about 40-50 mins of weights, and 20-30 mins of stretching after. On M, F and Sunday are appx 20 mins treadmill and then pickleball with shorter stretching before and after. I do a weight as heavy as I can handle to finish 2 sets of 8 reps to start. By the second set , 7th and 8th rep feels almost like I won't be able to finish. I record that weight and reps, and next time I do that muscle group, I will try for 2 sets of 9 reps, going up 1 rep each time. When I hit 2 sets of 14 reps, I will up the weight (5lb for arms and 10 for legs) and do 2 sets of 8 again.
I had PT for hip bursitis a couple years ago, and I noticed that one side of my body was stronger than the other (you have a dominant side of your body) so then I switched to doing a lot of the exercises on the machines with single arm or leg if possible. So leg presses I do one leg at a time on the machine. Each leg is like 60 lbs now, calf raises I do 95 lbs, single arm biceps are 40 lbs. I also do wrist curls and reverse wrist curls, twisting wrist,etc, all about 12-15 lbs. Pecs and fly I think is 60, inner/outer thigh is 50, etc.
I started out at low weights originally, and worked my way up. Treadmill, I could only do like 10 minutes at first. I get SOOOOO bored on treadmill, so I either read a book, or play games.

Consistency matters more than perfection or heavy weights. Once it becomes a habit, you are all set. If I don't have time for a full workout, I will still go to the gym and just do the weights portion. If I'm mildly sick, I might still go and just do stretching on the mats. That keeps up the routine.

To other lifters out there, a question: When you have to miss 2 or 3 weeks at the gym (due to sickness or a long vacay), where do you restart at when you come back? I sometimes go back in at 80% of where I was, but am I just being lazy? What do you do? (Pleasepleaseplease don't say you lift on vacay-I refuse to!)