How do I select and deselect only one object? I am in "preferences >input> object mode / mesh" looking for the place i can change the default settings in order to being able to select one object with LMB and deselect it with MMB. I only found the setting "(De)select all". But can´t find anything similar for only one object, thus, my changes affect all the objects that I might have in the scene.

Thanks a lot.
If you want to select with Left Mouse button instead the default Right Mouse Button you need to change this option: