You may play any number of lands on each of your turns.
Whenever you play a land, if it wasn't the first land you played this turn, this enchantment deals 1 damage to you.
Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)