Regarding weight training. Rob Newton is a leading exercise oncologist who I've studied. His recommendation is to start at 85% of what you can lift in any particular weight training exercise, and do it three times a week until it isn't hard to repeat 12 times. Then increase the weight until you can only do 6 reps. You want to keep a few reps in reserve, i.e. stop at 6 if you could, with maximum effort, do 8. Etc.

He usually is reluctant to issue general instructions, but in one video recorded by P.C.R.I. he was pinned down on a routine for anyone who was not in danger of breaking fragile bones or who was in serious trouble in other ways.

He listed six pin machine exercises:

Chest Press/ Seated Row/ Lat Pull Down/ Leg Press/ Leg Extension/ Leg Curl. I.e. upper body and lower body exercises, 2 or 3 sets, 6 to 12 reps each, 2 or 3 times a week.

Youtube vid: The Power of Exercise for Prostate Cancer https://www.youtube.com/watch

Newton lays out a concise description of what exercise oncologists have discovered in this article: Prostate Cancer Treatment with Exercise Medicine https://onlinelibrary.wiley.com/doi/epdf/10.1002/tre.884