How do kick-ins and throw-ins work when the ball crosses the touch line?

Under 6 and 7: no throw-in. A player from the opposing team to the player who touched the ball last before it crossed the touch line places the ball on the touch line and passes or dribbles it into play. Opponents must be at least 5m away from the ball until it is in play. The ball must touch a teammate before a goal can be scored.

Under 8 to 11: throw-in. The player faces the field of play, has part of each foot on the ground on or behind the touch line, uses both hands and delivers the ball from behind and over the head. The thrower must not touch the ball again until it has touched another player. Opponents must be at least 5 metres away until the ball is in play. The ball is in play once it enters the field of play, and a goal cannot be scored directly from a throw-in.

Source: Coles MiniRoos National Playing Formats and Rules, ball crossing the touch line.