You just need to find activity interesting for you

I used to do sedentary lifestyle most of my life until I found rock climbing 2 years ago

I go rock climbing to a gym 2-3 times a week now. I go there because I WANT not because I have to. This did tremendous job to my health and overall fitness. And this is sustainable in the long term because I don't have problems with motivation.

So my advice — find your sport, any physical activity you are interested in. If it becomes boring, don't hesitate to change it.

You don't need to be a sportsman and become good at something, you just need consistency to move your body , so care about your motivation. Good body will come naturally after some time.