Look at these examples:
If you want to be informal, use the "tu" form.
If you need to be formal, use the "vous" form.
Note the difference in spelling between appelle / appelles and appelez
It's tempting to translate Je m'appelle... as I call myself... but despite this being its literal translation, this is not correct.
I call myself... implies one's real name is something else, or a choice over one's name.
-> My real name's John but I call myself / everyone calls me Jack.
In French, the equivalent of this is Je me fais appeler..., which has the same implication of choice over the name.