I never weighed myself...scales are for fish. Yes that was the front page news on the New York Times when I was in the early eighties in NYC.
But really This's how any generally fit person would claim to be fit:
- waist is much smaller than the area around hips.
- have enough strength in legs to get to walk up many floors without painting too hard. I start to panting in my bldg (13 floors) after about eighth floor on an 80 y.o. frame. And I don't even watch what floor I'm on...our bodies are supposed to know better when to stop or slow down.
Tonight I did not feel had much aerobic exertion but I was late for dinner too so I did kicking an imaginary soccer ball in my living room with FULL force such that my other foot too get above ground in air just for a sec. In five mins my heart beat was maximal and I went for ten minutes slowing down and up again.

Invent your own workout! that's what we did as 3 y.o.!
- flexibility and balance -- and endurance with push ups, squats turning around midriff and with arms bending twisting in multiple ways.
Yes anerobic exercise -- running in place for even at maximal speed -- will get your heart rate in the zone within 2 minutes (my time) but you wish to make sure you don't get winded. so start safe and build up

dips come easy in stairwells; good for upper body and posture -- will keep shoulders straight.
Tell me what more YOU can improvise!
Good luck friend!

P.S. Nutrition is equally important; too many of us eat ultra processed foods, very bad. I'm sure Mayo would have info on it. It's a precursor of much diabetes/prediabetes in the world and here.