There are mods that make tactical easier, mods that make movement faster etc.
Can someone post a tutorial on how to un'pak' properly, how to change some fundament of the game and repak properly, how to load the mod etc, everything?
That largely depends on what you actually want to do. The simplest way to make mods for the main story is to create an Add-on that targets the Story in the engine. If what you're trying to do isn't possible in the engine,
https://docs.larian.game/Pak_Extractor_Guide will show you how to extract the pak files. You can also find some basic engine tutorials and documentation on that wiki, although it's still in the early stages.
