What level of soccer is your kid playing now? Frankly, unless he is on the top team of a major club, don’t think too far ahead. Kids will be likely broken up by age depending on how many show up. There might be an assistant coach or two snooping around. But for guys, getting a meaningful scholarship for soccer is getting harder by the day.
If he loves the sport, and it is affordable, let him just go and enjoy it. Many of the drills will be similar between all age groups but I suspect scrimmages will be segregated by age or vesrus kids one age group up or down.