If you really want to go full vanilla, I noticed you're on Linux so it actually runs ok there. But you'll still want Vanilla Fixer for the more modern renderer, launcher, and high frame rate fix.

https://mods4ever.com/project/DXRVanillaFixer

There are some huge bugs in the vanilla game though (Vanilla Fixer only does compatibility fixes not gameplay fixes). For example if you start a new game while in a game your inventory will become seriously broken. Before starting a new game you either need to restart the program, or enter the training first and start the new game from there (because starting training clears your inventory).

Also vanilla does NOT have autosave. When the game says SAVING when traveling maps that's actually only for the purpose of traveling back to the old maps and you cannot load from that if you die. Get used to that quicksave button but also make hard saves just in case!

Also vanilla will not allow you to save during infolinks (radio calls). Not a huge deal for a first time playthrough if you aren't rushing.