Mix real names, flowers, precious stones, elements, animals, objects, tastes, fruits, vegetables, words in languages that don't exist in your fictional world, nicknames.
Examples
Kingdom:
Rose + England = Rosland.
Salt + France = Salrance.
Silver + Humans = Silman Kingdom.
World = Platinum + Turtle + Banana = Platurna (Weirdly sounds like Saturn)
Some may sound weak, but you can play around with it for a bit, mixing and matching words you would like the world/kindgom to represent and come up with a neat sounding word.
You can also name them with words you come up with, like Ra'za Maln or slap your keyboard and add vowels between consonants until something good comes out.
Qawefku (just slapped my keyboard lol) sounds like a city either in a desert or populated by a specific species/race in your world that would have a similar sounding language.
Wish it helps a little.