Bring your 6 year old to a track and let him or her run around or practice sprints or whatever. Practicing staying in one's lane, understanding that the outside of the track is bigger so people start ahead in outside lanes, and standing behind the line while you say "on your mark, get set, go" are all good skills. There is also a good "at home" program at
https://runjumpthrow.usatf.org/index.cfm
this would be a long drive from NW but looks good
https://www.ccbtfc.club/
And I'd contact DC Speed through DPR to see if they will have a fall season
https://www.dcspeedtrackclub.com/teams/?u=DCSPEEDTRACK&s=htosports