It's not a sentence. "Oda megyek" (I go there) or "oda megy" (he/she goes there) would be a sentence. In these sentences (and in the phrase "oda menni”), "oda” refers to a concrete place, e.g. 1. You are pointing at a place while you are saying "oda megyek.” 2. You mentioned the place in the conversation before. (Have you been to Hungary? I'll go there. – Voltál Magyarországon? Oda megyek.) (The tenses are completely different in the Hungarian language. We often use present form, when we are talking about the future. It isn't slang, it's grammatically correct.) 3. In complex sentences, like "I am going (there) where I was yesterday." – "Oda megyek, ahol tegnap voltam.” Don’t mix up with „odamegy”. It means „go”, but it refers to the fact that the activity has a goal and an ending. The verb „megy” refers only to the activity.
I do not think there is a strict rule that adverbs come before verbs. This is more about what is emphasized, what is more improtant.
"Gyere ide" - "Come here" - neutral, asking someone to come here
"Ide gyere" - "come HERE" - emphasizing the location to go to, when someone is fooling around / misunderstands the request