Hello guys,
All the total conversion mods have their own .esm file. For example: Nehrim.esm.
The .esm files contain TES IV: Oblivion assets, without the quests, NPCs, interiors, worldspaces, etc.
Does anyone know how I could create a MyMod.esm file, with TES IV: Oblivion assets, without unneeded content like quests?
I want to look into making my own total conversion mod, of my own lore and own worldspace.

You probably need to read
You probably need to read some tutorials, but you should be able to copy Oblivion.esm to a new location, rename it MyMod.esm, and then copy it back to the Oblivion/Data folder. Now open it in xEdit, and remove what you don't want. You might want to join the Arcane University Discord Server, and learn about modding. It's for Skyrim, but most principles apply to Oblivion as well. Very few people are beginning a modding project with the Oblivion engine in 2022...