Sorry if my suggestions have already been mentioned. This is all just my own experience, I'm not quoting any science.
Exercise requires a breaking in period. It's realy tough at first and not very rewarding. So you just have to force yourself to do it.
Just take an example: pullups.
It feels lame not being able to just a single one so you would then think 'well how do I even improve at all, then?'
But the human race has been exercising methodically for a very long time. There's always a way to start at the absolute bottom and make your way up.
If you're unsure how, then just do a quick google. In the case of pullups, what you actually do is jump up tpo the bar a\nd lower yourself as slow as possible and repeat until you can't do that any more. If you can't even do that, you find a way to counter your own weight or buil those muscles with a different exercise that doesn't work them as hard.
Can't even walk for a few steps without getting out of breath? OK, sit in a chair and practice rapid and deep breathing. It will make your entire body tingle if you're that out of shape.
Anyways, once you're exercising regularly for a few weeks you get a positive feedback loop and start to enjoy doing it and look forward to doing it.
If you are looking to actually take care of your body and actually exercise for health, and not the human need to prove something to people who don't care, (and end up with knee and back surgery at the age of 45), then I recommend just following some simple yoga for beginners on YouTube for the net 6 months. It also means you don't need to go anywhere, you can do it from your bedroom. You can do it at your own pace, pause the video, take your time and nobody is watching you so it's a nice safe space.