Have you ever picked up a book and on the first page you read that “Mdonkotherm the Great Aflunderer is traveling to Isnodergum for the Jxazpouoiany Festival”? Back on the shelf it goes: I want to read a story, not learn a foreign language.
Can you use big new names you’ve invented? Sure. But you have to introduce me slowly. First, introduce me to Mdonkotherm and make me like him. Use only words that I know. Then tell me he’s an Aflunderer and explain what that is and why it matters. Then get on with the story. Why am I reading about Mdonkotherm? What’s his goal? Why should I care? Once I’m hooked, THEN you can tell me about Isnodergum and the Jxazpouoiany Festival.
Take Tolkein for an example of how to do it right. In the beginning we meet Bilbo, Frodo, Merry, Pippin, Sam, and Gandalf: all names that I can pronounce without much effort. The names are simple and when we begin to learn the more complex names of people and places later in the book, we’re already hooked and we can handle it.
Don’t dump your world’s new language on me, teach it to me.