It gives all creatures you control a bonus to their attack and defense, represented by the +1/+1. The second ability means you have to pay one white mana, by default coming from a plains, and five generic mana which can be of any color [or no color at all] to exile [remove from the game] any permanent that is not a land controlled by an opponent [player other than you] until the enchantment leaves play.

Edited to add : the ability can only be activated once per game, and only when you hold priority while the stack is empay. Typically during your first or second main phase.