When I was released from the hospital, I had a cadre of home PT, OT and nurses. Sometimes I had 2 appointments back to back on the same day - nurse then PT or PT then OT - and I recall that as super exhausting. The PT always took my o2 and blood pressure first and once cancelled our session because BP was high and exercise elevates it. The initial PT stuff was simple like balance while holding the counter, marching in place also while holding onto the counter, lying down to lift the leg (with then eventually without his help), hamstring curls, heel slides and leg extensions on a chair. Everything was super gentle those first 2 weeks or so, really less about exercise and more about testing movement.
eta: I have to say my movements were pretty pathetic early on and made us laugh. He'd say "fire that quad" and I'd say "I'm firing, this is as good as it gets" as my leg raised not at all!
I hope the surgery is uneventful and you're home relaxing comfortably in your favorite chair toute suite.