The title of "Righteous Gentiles" bestowed by the State of Israel only applies to people who saved Jews during the Holocaust. It's a secular title that could be given regardless of their beliefs. But you were not there!
Now, the term "Righteous Gentile" in Judaism applies to any person who keeps the Seven Noahide Laws. According to the Torah a non-Jew is not required to keep the Jewish Law. But he must keep that seven Laws.
One of these laws fordids to do idolatry and says a person must believe in and serve only the One true G-d. If you don't belive in Him, then I doubt the Hebrew term Chasid Umot HaOlam (translated to English as Righteous Gentile) would apply to you.
But speaking in English, are you a Gentile? Yes, of course, all non-Jews are Gentiles (others Nations). It's obvious that if you are not a Jew, you are from another nation, all persons belong to a Nation.
Do you consider yourself righteous? Are you a good person?
If so, the you can say that you are a righteous (Honest, good) Gentile. But not in the sense of the term "Righteous Gentile" as it is stated by the Torah.
Just for you to understand it better, in Christianity, for instance, you can be considered a good person, honest, loving, generous, but if you don't get baptized, you don't save your soul. (According to them)
In Judaism, you don't need to become a Jew to save your soul, keeping the Seven Noahide Laws is enough for someone who was not born a Jew. You can be a very good person, do good deeds, be honest, and Jews will be gratefull to you if you support them. But if you don't keep the Seven Laws, you don't save your soul.