I was the opposite of sport 11 years ago. Now on track to prepare to my 9th full marathon (plus registered, trained, but did not start on 4 due to injuries and sickness related to overtraining, covid lockdown, etc).

I would invert the search for motivation upside down. Sport is essential for mental + physical health (beauty, good mood, productivity for less abstract terms). Start with sport as the base line. Set your weekly load according to your current shape. And then ask every time: is there a reason NOT to run now? A real reason, not an excuse "I do not feel like...". Not sick, not injured, not overtrained (objectively from heart rate or body battery indicators, not own subjective feelings), the weather is below 30C and above -10C without heavy rain (or a treadmill available). That's it for me now. I just know I will feel great after 1km no matter how I feel before.

For novices, I would strongly recommend to run slower and have fun. Avoid overtraining as much as possible. For some, even 2km twice per week is too much. I've seen many friends hated running just because they tried to run too fast for too long and felt overwhelmed.

Register for a 5K in a couple of months. Races are the funniest part of the running story. But races are not just a distance on a day X, they are all the time of training that makes them joy, not an exercise in masochism. They discipline and motivate.

"If it feels like work then you are doing it wrong" - a qoute I read long time ago and it helped me a lot.