In my opinion, there is no real formal or informal way of asking for someone's name.
What's your name?
I would say is as close to informal as you can get, because of the use of a contraction, rather than
What is your name?
If you really want to be informal about it, you can use ebonics.
What's yo name?
What your name be?
Never do we ask someone what they are called, which is what the spanish,
cómo te llamas translates to.
What do you call yourself?
To say that in English would imply that you want to know their alias/nickname/title
We have no substitute for
name. Unless you want to get super informal and somewhat objective, you might get away with using the past participle
What are you named?