Buy yourself a basic weight lifting bench, a barbell,a couple of dumbbells and about 100 lbs in weights.
Do a basic workout two or three times a week then work your way up.
It doesn't matter how you do it at first, as long as you're careful and keep the weights light at first.
Once you get past the first month then you can start studying for a more intense workout and build from there. Or just maintain what you have.
There's more than enough resources online to guide you every step of your development ..... forums, blogs, lemmy, fediverse, YouTube, websites.
My wife has a chronic disease and we have to stay at home all the time now. I don't go out much any more. So at the start of the winter I started a workout routine. I've never done one before and I felt dumb at first because I could barely lift. I've always thought I was strong and I work in construction but not intensely so I was surprised at how little I could actually lift.
After the months of three days a week, I'm doing a lot better now.