Hi, I've bought these assets and have been struggling a lot to implement a simple tilemap scene with them.
I know the ground tiles are wrong, but even ignoring them, I'm completely at lost on how to make the long tables fit correctly on different tiles or how to adjust the pivots.

I'm looking for someone that can create a scene with these and go on a 1:1 with me to teach me exactly how you did it.

One condition is: I must still be able to track which sprite is in which tile, because I'm creating a tactical battle system and need to know what each tile in the grid contains.

Please let me know how much you would charge and when could we do it. Thanks!

Those does not look like a tileset you could simply configure godot to use for auto tiling, those look like tiles you manually import to a tileset then one by one manually place in your scene. What you have is more of a 2d art asset pack which could be a good addition to a functioning autotile setup.