Here are 5 ways to introduce yourself in Greek!
So, let’s start with the most common one!

*Με λένε + your name WITHOUT ARTICLE & WITHOUT the ending -S for the Greek male names

*Είμαι + ALWAYS WITH ARTICLE

*«Λέγομαι» και «ονομάζομαι» WITHOUT ARTICLE

Number 1 and 2 are the most common ones in both formal and informal situations.
Number 3 and 4 are slightly formal. In all 4 of the above you can add your last name as well.

Number 5 is neutral
Το επίθετο / το επώνυμο = last name

Have you used any of them with natives or at your Greek language lesson?
Which one do you prefer?