He is only 6... my kids are now 14 and 20. Neither one was a gifted athlete, and we just had a rule that our kid had to be involved in one sport in a given year. They don't have to play all year around, or on traveling teams, or even ever make varsity. The sport was their choice (the one limit was that if they picked a sport with expensive equipment, we wanted them to stick with it for at least two seasons). So except for the pricy equipment deal, we let them quit at the end of a given season or paid for session with no pressure from us. Between the two of them my kids tried soccer, swimming, softball, volleyball, cross country ski racing, figure skating, tennis, golf, and dance. Maybe a couple more I have forgotten

They were mediocre at some, and epic failures at others. The sport that "stuck" for both of them was volleyball; go figure, I hate playing volleyball... I never would have guessed that they would pick it, but it is entirely their choice.
We set this expectation early with our kids, and it is a pretty simple ruleset for them to remember. They had a lot of flexibility within it. I never griped about fees or driving (even when I wanted to, some of those all weekend volleyball tournaments were lllooonngg...) because I think having our kids be involved in SOME sport for the long term health benefits was important.