In my most distinguished and long-term example of "what are the planets named", they are both named after their associated god/goddess who is mythologically responsible for crafting the planet, for as much or little as that is actually true. One example is Almaera which is an Ekaeli word, based off two Malelri words, Alma (possibly even Al Ma) and Era. Era means land. Alma means shadow (and might have originally broken down to be like Light Dark) and shows up in many people's names. Why is it the "Shadow Land"? Because it was mythologically MADE by Malelri as a copy of the other planet which is habitable as well, Carmen. Carmen is named after the ancient goddess Carmenjia (who is not actually the same person as Lady Fate, the governing well known well branded goddess who borrowed the name Carmenjia). The jia part humanizes it. Carmen now refers only to the land of the planet or the personification of the goddess of the planet, but you would not call her Carmen to her face, you would likely call her Lady Fate or Carmenjia, or if you're in the know, you'd call her by her given name granted by her mother and her father's surname, Iydra Shovak.
On Almaera, at least the section we most commonly write, we would base the names off the Ekaeli language OR the predecessor Malelri language which uses only single syllable simple words which have ostentatiously many meanings for a single sound with the specificity derived by telepathic connection. Not useful, but this results in some places, such as "Dau", which... might have meant south or water or waterfall or land by the waterfall. Or the "oth" ending, which turns it into the name of a city will be applied. There is Endoth, which is "End" + "Oth", End likely originally meaning "mountain" or "rock" or "by the mountain" or "in the air" but now it literally is just "mountain city".
Estavan has its own languages. Nomadic Almaera does not have defined place names, but instead defined territory owned by certain tribes, whose names will reflect their primary territorial claim. Such as "Westvale".
Carmen was originally populated by human colonists, a very long time ago, and its names loosely reflect its ancient history as a colonized world, with a selection of them having clear nods to their origins, and others having shifted into local conlangs. Some of this is shown in our editing process, where "Mudville" became "Cairavaire" as we used the region more and eventually decided to give it a proper name. Others are certainly still in their original spirit. "Potatoma Shire" was the first draft but now it's on the map as "Potatomashir". It has not evolved much. It is 100% canon and will likely always remain.
So if I were to name a new place there, I'd likely give it a cute English colonist pet name and then devolve it over many many generations of repeating it to see where it falls apart to simplify it a bit.
The two planets can see each other in the night sky and have had past space travel connections before that technology sort of went down the tubes (teleportation developments sort of ruin space travel), so it was necessary the planet as a whole be named, even though devolution has resulted in Almaeran continents being very separate from each other. Even the largest continent being extremely divisive from north to south people still know that they're legendarily on Almaera's body replicating the entire other planet in the system (badly of course). The same language is spoken all over the world, to varying degrees of dialect so I'll generally begin by drawing on the bank of Ekaeli words I have to work with, or appropriate Ekaeli sounds, and then if the name is not in the "main stage" where that specific dialect it used, I'll evolve it a bit over time based on the rules we have for how, say, nomadic Ekaeli or Tavaroth Ekaeli functions versus "contemporary Ekaeli".