I was never into any sport and after a few attempts of going to the gym and lasting a few months at best, I doubt I'll ever like it. Walking is fine, but it's not an option for most of the winter and it's not enough on its own for me.
The trick for me is that I found out that I actually enjoy hot yoga, been 1 year at 3+ courses per week. The gym felt like a chore that I "had" to do, Yoga actually feels like a mix of fun/challenge/meditation/workout that keeps me interested (which is the key for me)..
If Yoga is not your thing, there are lots of activities that implies some form of physical activity that might hit your mark..
We can adapt to most things. That means we can make our body adapt to bed rotting all day or working out first thing in the morning. It just takes a consistent schedule. To paraphrase a running monkey from Bojack Horseman, "it's gets easier, but you gotta do it everyday. That's the hard part, but it does get easier."