For anyone looking to get started I highly recommend the StrongLifts program and the associated app, both free [1].
I neglected strength training for a long time because every time I tried to get started I would feel overwhelmed. Then I tried StrongLifts and loved the fact that it's just 5 exercises, but provides pretty much a full body strength workout.
The guy who developed the program has put a ton of effort into making sure it's detailed and accessible so that pretty much any question you could have is answered.
Powerlifting.
Solitary and meditative if you want it to be; social and uplifting if you don't.
It's healthy in a variety of ways (including bone density; physical activity; higher BMR and glucose metabolism; improved cardiovascular function). Also being strong is useful surprisingly often.
Unlike many things in life, your progress is almost entirely dependent on your consistency and the effort invested, with the exception of (hopefully) temporary setbacks like injury. Hitting personal records and milestones feels particularly good because you know you've earned it. It's hard! But it's also not so hard that I'm liable to get discouraged.
Lots of people prefer bodybuilding style training, but there's something magic about the barbell for me. Olympic lifts are also a lot of fun, but they're more technical and you need more gear and space.
Also it's much easier to quantify your strength progress (I have a literal spreadsheet), and it feels less vain than focusing on looks (not that it isn't a significant bonus).
Dunno. Feels good. I'm gonna keep at it. Two thumbs up.