I started lifting again 4 years ago around the time I turned 40. At that time my father's health and mobility were very poor and he was only 66. I was starting to have some of the same symptoms and issues.
Since then I've been lifting on average 6 days per week. I change my routines up from time to time to not only keep things fresh but also to keep my body from adapting too much to a particular program.
One thing I've found helpful is keeping a training log, much like many here do for their shooting. I keep track of the exercises, sets, reps, weight, and any pertinent observations. I can then refer back to make sure I'm alternating exercises to keep from focusing too much on those I like most. I can also track progress, etc.
I bought some smaller 1.25lb plates and use them along with 2.5lbs as my "old man weights" to make moderate incremental increases in resistance when my current weight is too little but a 5 or 10lb increase may be too much.
I increase my weights when I FEEL I have more to give and what I lift can ebb and flow day to day and week to week based on time of day, calories in, injury, amount of sleep, etc. I can often easily add 10 more lbs to a lift in the afternoon then I can to my normal 5am workout. The training log helps me track everything and know when its time to add some more weight. That said I do not "max out" or go for PRs. I try to lift smart and keep my ego in check. I'm not trying to be a power lifter or compete with 20 somethings in the gym. No one else is paying my orthopedist bill or mortgage or feeding my family if I hurt myself.
Eating and sleep is super important too. I feel too many people try to get stronger or bigger while simultaneously trying to loose weight. I feel those are mutually exclusive. You can get leaner (perhaps) but focus on getting quality calories, enough of them, and on the lifts. Not on the scale. You'll see your clothes fitting better and know well enough from that how you are doing. Did I mention good sleep is very important? Cause it is.
I started 2020 with a trainer 1-2 days per week. Like with shooting, I wanted another set of eyes on my form and to keep me from cheating myself. He also keeps me accountable and focused on the exercises I need to reach my goals and not just those I like the most (i.e. don't skip leg day, etc)
At two weeks shy of 44 I am 6'4" and 253lbs at about 11% body fat. I have no chronic pain or physical complaints. I can play with my 8 and 11 year old boys and keep up and they think I'm "super strong" "like an Avenger". There are few things that make me happier than to be a hero in my boy's eyes!
Sorry @Bio this got a little long winded but I thought it may be helpful. I just wanted to say you got this and go at your own pace!