‘FIFA’ soccer’s world governing body set the laws of the game. Each country’s soccer federation withholds the laws with in their country. The youth part of the federation withholds the laws with some small changes for the ages of players with the consent of the National governing body. (US Soccer - State Office - Club)
Clubs with in-house program fallow the same FIFA laws. At the state level - state offices (Eastern Pennsylvania Youth Soccer) allow small changes to their own rules which will benefit their program and players.
It is important you have an understanding of the FIFA Laws and also any local rule changes