I highly recommend to start frequently exercising - Build discipline and initiate a heartbeat to act as a foundation for future habits.
I'm following a routine called Stronglifts 5x5[0] and it's dead simple, but yet incredibly fun and easy to gamify - You're progressively adding weight and seeing results almost immediately. I use an open source app called Track and Graph[1] to track, and you guessed it.. graph my results - It's a rewarding feedback loop!
[1]: https://f-droid.org/en/packages/com.samco.trackandgraph/