As an old person, a lot of my aches and pains now come from fitness-activity injuries in my youth. So may I suggest MODERATION. Watch the wear and tear on your tendons and cartilage!
For sure. People need to know there's a difference between getting into shape, and getting ripped.
When I started my most recent exercise stint, I took my workout program and started with 4 sets of 25 reps at 2.5lb. Once I could do the last set without any sort of struggle, I upped it by 2.5lb.
This has many benefits, such as strengthening supporting muscles, letting your tendons and ligaments slowly get used to moving the weight, and cements in proper form so you don't end up doing cheater reps at higher weight.
It's more difficult than many might expect. For instance, my 10rm on bicep curls is 45lb, but my 25rm is 15lb.
Some of us can only dream of that, because we have unrelated health issues that prevent us from exercising, and a shitton of other stuff. All we can do is hope that this isn't the healthiest well ever be, because that thought is fucking depressing.