way to go to all of you. I appreciate ya'll encouraging each other forward. I've been slacking a bit lately but managed to hit the gym before work this morning, so I'm not feel quite as convicted by this thread :)

For fitness: pick up the Tactical Barbell books. Base building is the "get in shape to get in shape phase." if that's too rough for whatever state you find yourself in, check out the /r/tacticalbarbell community on Reddit. Someone there made a "pre-base building" phase.

Simple standard body weight exercises are a good start. You can do various push ups. Regular, angle your legs upward to work your upper chest. Non weighted squats, lunges for your lower body. Planks for your core strength. you can put a broom handle between a couple of chairs and lay down and do pull ups and reverse grip pull ups for lats, and biceps. Start slow and don't get discouraged. Get in about three times a week. Off days a good walk will suffice for aerobic activity. Throw in some stretching before each session and you're off to a good start. Later you cam add bands to get some increased resistance. The main thing is don't get frustrated, work at whatever pace is reasonable, stay regular at your routines, and you will get there!

Brian, all the above obviously is great advice. All I can add is to just move. Get off that sofa and or chair and just move. Walk. Do what is comfortable for you.
I am 66 years of age. I use kettlebells to stay in shape. I can swing a 53lb kettlebell for 20 reps at a time for a total 200 plus reps with about 120 seconds of rest between sets. Not bragging at all. This is just what works for me. Your milage may vary. the alternative is getting fat/lazy sitting down. You CAN do it. It will be hard, but the rewards will come quickly. Even recovering from a sickness we were made to move.