The enchanted land will have the land types Plains, Island, Swamp, Mountain, and Forest. It will also have the mana ability of each basic land type (for example, Forests can tap to produce {G}). It still has its other subtypes and abilities.

Giving a land extra basic land types doesn't change its name or whether it's legendary or basic.

If the target of an Aura is illegal when it tries to resolve, the Aura won't resolve. The Aura doesn't enter the battlefield, so you won't get to draw a card.