This has confused me I've seen article on here and other sites call it Earth-0 but i have also seen people call it Earth Prime which when i hear it i cant help but think of Superboy-Prime and evil things.

Also if it is Earth Prime why not call it Earth-1 because it sounds odd to go from Prime to 2, And if it is in fact Earth-0 then what and where IS Earth-1 since we have already seen people from 2 and 3.

Indeed the main continuity earth is called Prime Earth. There actually is an Earth-1, it appears in the Superman: Earth One, and Batman: Earth One comics.

yes its earth prime or new earth as the wikia likes to call it.

earth one is as @jphu8414 described it, earth 2 has its own book, earth 3 is where the crime syndicate comes from, and so on. if im not mistaken i think the young justice animated U is earth 16? i think? i believe arrow might have its own earth as well but i cant be sure(hopefully it does and it soon becomes the same as the man of steel earth...fingers crossed!)

its either back to infinite earths or maybe 52 earths considering how popular that number is with DC these days.

I just posted a long answer to a very similar question on another thread on this board. Why don't you click this link to read that?

http://www.comicvine.com/dc-comics/4010-10/forums/what-different-between-earth-prime-earth-one-1547349/#2