At the gym I go to (Planet Fitness, nothing special) I’ve seen some dudes in their 50’s who look like they could kick some ass.
I’m 50 and I’m stronger right now than at any time in my life. I never took weightlifting seriously until I had a major knee injury in 2013. I was fat, had high blood pressure, and my Dr said I needed to quit drinking or die. This includes my 20+ years in the military. Yeah, I barely passed the PT run my entire career. Find a trainer that will walk you through baby steps. It took me 3 years to get where I am now because of the atrophy after my injury. The time to start is yesterday. It only gets harder the more you put it off.