Luffy is a pirate, an outlaw. Drinking beer or whatever is the least of his crimes. He drank Sake with Ace and Sabo when he was like 6.

What is Luffy's favorite drink?

Water. Toto handing Luffy a small amount of drinkable water. Water (水, Mizu^?) is transparent, odorless, tasteless liquid. It's a vital substance to all forms of life.

Can Zoro get drunk?

Though Zoro is quite a jovial person when he gets drunk, nothing in this world will ever really help him get along with his Straw Hat rival, Sanji.