Universally across cultures (at least as far as I can tell) the word for the planet has always been earth, soil, land etc. Maybe play around and think about the sort of languages your people speak, what they sound like and what sorts of letters they use (I doubt elves have very many k's or g's in their language, for example, but dwarves may) and try to compile a few names from that and see what sticks. Once you get around to placenaming, it can be fairly easy, as most places are named after geographic location, nearby landmarks, or famous people/saints/gods/etc. so you can just play with compound words.

For generators I like to use Fantasy Name Generator They seem to have a reliably pronounceable output across most of their name gens