ok, luna is in Malas, a new landmass that was introduced in the Age of Shadows expansion. If you go to any moongate, and click on Malas, Luna, the bank is not more than a stones throw away from it. It is where the mass amounts of vendors are found too. The place is very overpriced, so when you hear "luna prices" that means the inflated prices at the vendors placed there.

Feluccia is of course what used to be the only landmass to play on, where pvp is the way of life and this is where the champion spawns are, that reward power scrolls(scrolls that let you take your skills to 105,110,115,120),

Trammel is the mirror image of it, but no pvp, and less desolate. Its where most people hang out and hunt. Due to the addition of trammel, Fel has died pretty severely, and I would say 90% of the folks that play, dont leave Tram, as the risk there is pretty limited, other than wherever you hunt.