What are we supposed to call God?

Most call him "God" or "The Lord". But those are titles. There's jehovah, but I think that's a vowel of some kind in Hebrew. Then there's Yahweh, but don't people think it's wrong (?) to use that for God? What does the bible say, or does it say, what we are supposed to call him? I mean, surely he has a name? Thanks!