on rightclick on sign:
    line 2 of clicked block is "checkpoint"
    line 3 of clicked block is "[rightclick]"
    set {checkpoint1.%player%} to location of player
        message "&6 2つ目のチェックポイントを設定しました!"
    if player has permission "skript.admin":
        message "&7Location of player"
on rightclick with nether star:
  cancel event
  if clicked block is sign:
      stop
  if {checkpoint1.%player%} is set:
      teleport player to {checkpoint1.%player%}
      stop
  else:
      message "&c 2つ目のチェックポイントが設定されていません!"