At almost your age, plus being overweight, I started to get scared that I would never be anything approaching fit and was worried if I fell over, how embarrassing it would be to need assistance to get up! Most exercise regimes I had tried in the past were too difficult for someone like me - so I always gave up.
After a lot of searching, I found Tom Morrison's Simplistic Mobility Method. It's very flexible - you progress at your own pace and he gives other ways of doing the exercises if you find them too difficult. And when you get better, there are things to make the exercises a bit harder so you still get something out of them.
Tommorrison.uk