Can you be a Hellenic witch and an eclectic witch? Because I was thinking Hellenic with would be the religion and the eclectic would just be what you practice?

Yes, you are exactly right! Witchcraft doesn’t need religion to be a part of it. It’s just a practice on its own. If you wanna incorporate religion that’s fine too!
So, yes, you can be Hellenic and eclectic. I’m basically that as well!