You have lots of good answers posted but here is the trick...You have to START.

You don't need to sign up at the gym today and build a schedule to work out. That's way too much commitment. Instead just go outside.

That's it. Just put down the phone and go outside. Spend 5 or 10 mins out there. You didn't run a marathon, but you've done something today. Maybe later today you can go outside again. Tomorrow so the same thing. Put the phone down and go outside for a short time.

You gotta start somewhere, so make it easy and start small. Eventually you'll spend more time outside and less time doing nothing. Maybe you see cool plants and start getting into gardening. Maybe you find that walking isn't so bad and you find a park with a nice trail and work into jogging? Maybe the kid down the street wrecks his minibike in front of your house while you're outside and you stop to help and think the tiny motorcycle is cool and get inspired to start riding.

tldr- Don't just pick someone else's hobby. Put down the phone and go experience life outside your home. The hobby will likely find you when you start paying attention instead of distracting yourself.