The kick off is a new part of the game at under 11 & Under 12 and can bring in some varied approaches to receipt.
If we look at the geography of the pitch 1st then it will help look at the formation.
The pitch is half of a standard pitch playing width wise. So 40 metres wide and around 60 metres long. The kick from kick off must cover 7 metres.
When I was coaching at this age group I looked to rugby league for inspiration. In rugby league they receive kick off in two lines with some covering players behind the two lines. Who ever catches the ball passes the ball o someone running from deep at pace.
So in our sport I deployed a line of 5 around 10 metres back, with another line of 5 10 metres behind them; with the remaining players covering behind in case of a deep kick. When I coached it was 2 players there but now it is 3 as the game is 13 a side.
Initially I encouraged players to catch the ball and pass to a player close by running at pace. I progressed this to passing the ball 2 away then passing to a player running from deep.
This formation is relatively simple and it is successful. Given these it grows confidence within your players. This will have be tweeked and even changed towards the end of under 12s in preparation for playing on a full size pitch; but it will put the foundations down on how important formation is and will help when you move on to coaching more complex kick off formations.