Formal:
* Bonjour, je m'appelle Larry. (This is the most common and polite way to introduce yourself.)
Informal:
* Salut, je m'appelle Larry. (This is a more casual way to say hello.)
* Bonjour, je suis Larry. (This is a slightly less formal way to say hello.)
You could also say:
* Enchanté, je m'appelle Larry. (This translates to "pleased to meet you," and is a more formal way to introduce yourself.)
Remember to pronounce Larry as "La-ree" in French.