"I do not eat meat, I am a vegetarian."
Translation:Δεν τρώω κρέας, είμαι χορτοφάγος.
Correct! Some adjectives have 3 different endings, one for each gender, but others only have two. This falls into the latter category.
Yeah, the pronoun being optional (in this case "εγώ") in the majority of cases makes it seem like δεν needs something behind it.
I have to mentally add the pronoun to place it correctly