pls help me with prayers?

Hiii I hope you are all having a nice day 😊! I have a question about praying when it comes to Hellenism. I am a beginner and I don’t know the ways of how a prayer should go, do we usually have to make a Khernips to purify ourselves then pray? do we have to make Khernips every time we pray to Gods in different hours of the day so we can be cleansed?

Also when it comes to praying on altars, is Goddess Hestia the first and last ouranic Goddess we should pray to? What about when it comes to Chthonic Gods? Is there a first and last Chthonic God/Goddess to pray to?

Im sorry if there is so many questions, I don’t have any pagan friends also I am a little bit curious because I usually say small gratitude prayers to the Gods without khernips and I don’t know if I’m doing it wrong. I would love to know 💕