Just because others go to the gym, it doesn't mean you have to.
Your alternative toolkit:
Just go for a walk. All you need is a pair of walking boots, waterproofs and possibly a guide book to local walks.
You'll discover places you never knew existed. Coastlines, hills, mountains, old railway lines, canals, riverbanks, fieldpaths, woodlands.
It's good for both your physical and mental wellbeing. You might even meet other walkers, some of whom are like you trying to get away from the dreaded gym.
Optionally you could also buy this book.
https://www.amazon.com/Get-Free-Ditch-Total-Fitness/dp/B005EP2D10
But you can’t get near the coast due to caravans and motorhomes ??