Healthtree has a wellness, physical health chapter.
My husband took part in a fitness myeloma clinical trial. They did low impact walking in place, using their arms as well. They used small weights and did some stretching. Some doctors discourage doing a lot of torso twisting if you have spine issues. Swimming, walking, yoga etc all encouraged.

I have been a TaiChi practioner for 25 years. I try to do it every day...it's the best exercise for balance, strengthening,stretching, calming the mind, breathing.
I taught it for many years until Covid caused my private students to leave....
If u can't find a class check online.

Walking and going up and down the stairs

Anything low impact to avoid bone breakage

Unfortunately, I can't walk very far or stand for very long. I exercise in a chair or laying down. I used to do silver sneakers and step aerobics in my younger years.