I've never been during the day on Friday in the school year, but I've gone on several Friday nights early in the season and they are great times to go. I wouldn't think you'll have to wait more than 15-30 minutes for anything besides Invertigo, Firehawk, MAYBE Flight of Fear, and quite possibly WindSeeker (we'll see how it handles capacity once it opens). I guarantee you'll have a lot of fun.
Welcome to KIC!