You should be fine then if you don't have to provide photos to individuals. It seems unrealistic for them to expect to see each and every photo from the event posted online, but of course, people may have unrealistic expectations and might think they'll see 'their' picture; so like John discussed I think it's a matter of helping people understand why select pictures may have been used.
I've been a photographer for, well, forever and I can still manage to mess up. But I also know how to salvage something or somehow get whatever it is done. I think with sports and events it takes being able to think on your feet and adapt as you go.
It sounds like you've been improving but maybe you could still use more learning and practice. You could try going to community events just for fun, as long as the event allows participants to bring in cameras and take photos. Think about how you'd go about getting photos of the event - go early, find good vantage points, see what the schedule of events for the day will be, etc. Notice how you can get pictures in a crowded area, of smaller tables, larger tents or whatever. Keep practicing.
And if you haven't yet, or maybe you have, if someone 'booked' you that seems to imply paid/compensated pro work; so it would be good to make sure you're learning how to appropriately license usage, etc. It seems people learn a certain amount of info. and learn terminology but haven't yet necessarily always learned all that's necessary to know. You want to make sure you're covered to avoid dealing with problems later. You might if you haven't yet take a look at pro photographer organizations
American Society of Media Photographers - Homepage or PPA.