I am curious how to change the name list in my game without downloading someone else's mod. I want to customize it for MY game. I am INCREDIBLY new to modding. Is it difficult? I have TS4 Studio.

EDIT: I figured out how to add my own names to the game by using someone else's mod, but it still has EA names that I don't want. How do I remove them from the game?

If you open one of the existing mods in Sims 4 Studio from the 'My Projects' button, you can simply modify it to your own preferences.
Or you can use the name / Instance ID of the resources they used to look up the EA originals from Tools > Game File Cruiser and add them to a new package.