U5 thru U8 do not use penalty kicks.
For U5 & U6, direct free kicks are taken from the approximate point of the foul. (But they should be moved back "10-yards", i.e. 5 yards at this age, from the goal to allow defenders without creating a dangerous point-blank situation.)
For U8, fouls committed in the penalty area by the defense are punished with direct free kicks take from the nearest point of the penalty area line parallel to the goal line. (Similar to FIFA procedure for Indirect Free Kicks taken in the Goal Area.)
U10 and up, unmodified.