It's hard. My Mom after she moved here and I have no reason think before moving here was different, just sat.
Sat in her chair all day watching TV and reading books. Get up to go potty. Get up to go just outside the door to smoke. Get up to get a beer from the fridge because I, the Evil Son, refused to fetch fresh beers for her. (Drink all ya want mom but you have to be able to totter down the hall to go pee and then totter to the kitchen and back to your chair.) Walk around anywhere to even pretend to exercise? Heaven forfend.
I didn't want her here. I moved six hours away from the folks for a reason. But after the sisters cleaned out the valuables, like silverware and dad's coin collection, and then emptied her bank account and mailed both sets of the fucking keys to her van six weeks after they vanished,, well, what can you do? They left her to die.
So we went and picked her up and moved her into the spare bedroom. She was down to one egg in the fridge and a couple of slices of bread that were on the edge of turning green. I'm not getting over this.
Anyway. She was here for almost four years and overall, it was good. Getting to spoil her and hear her stories was totally worth the cranky spots. And we both had cranky spots..... she was still my mommy and I was still her little boy and here we are as adults, so, some friction.
Move Dad in. Put him in the guest/spare bedroom. Get him a decent chair and run some cable to the TV in his bedroom. Sort of like a one room apartment but make it /his/ space. Hang some of the pictures he likes, put up some shelves for his knickknacks. Make room for a chair he likes in the living room. Get to know Dad better... as more than just "Dad" but as the man he is. You'll be surprised what you learn.