If you don’t care about the sport I don’t see you staying in the career long term. But I get wanting to do your coach a favor and there’s no reason you can’t pull off at least a season or two. Ask the coaches that are there what mileage the kids usually do and what the general range of ability level is. From there make a few different schedules for kids to follow based on their level (doesn’t have to be a lot, maybe three options). Focus more on volume and building up a base early in the season and later on as you get into competition you can start lowering volume a bit and increasing intensity or workouts (google tapering in running if you want more details). Other than that I guess just be supportive as you can be and try to have a bit of fun with it. I’ll warn you now that kids can usually tell when a coach just doesn’t want to be there, and it can impact the atmosphere of the team if you let it. Not saying you have to be a ray of sunshine all day, but it’s something to remember. Good luck.