When you have an U21 squad you will automatically play U21 league matches against teams from your league level. Every three days you will be drawn against two random opponents that have a youth squad at that moment. This way, teams can start and stop participating in the U21 league at any time during the season.
You can be drawn against any team from your league level, also from different subgroups. If you are for example in league 3.1 you can get an opponent from league 3.2
If there are few teams, or an odd number of teams with a youth squad in your level you can also play against an opponent from a higher or lower league level
If you are in the lowest league level and there is an odd number of participating teams you may also get no opponent at all.
Selection of who plays (at home) against who is done randomly.
The U21 league matches count as league matches when it comes to experience and cards. You can divide your 20 league matches per season over both the normal league and U21 league matches. If you get a card in an U21 league match this card will count in normal league matches as well.
Example: if a player played 13 U21 league matches and 7 normal league matches he will not get experience for any further league or U21 league matches.
U21 league matches give 450 experience points per match, while normal league matches give 500 xp per match. This means it's slightly better to let players get real league experience.
You can see the U21 league standings in the U21-tab in your league overview. These standings contain all teams with an U21 team in your league level (all subgroups combined). If a team loses his U21-squad during the season he will be removed from the standings, even if he did play matches.
Because teams can be added and removed from the competition during the season, not all teams will have the same number of matches played.
