Control Issue

[Pikminfan33]

I was checking out the control scheme in LoE and I didn't know what "Tertiary" was, I ended up clicking it and set it to left mouse click and in game, every time I click, it brings my mouse to the center of the screen and scrolls the camera. I'm using a Laptop, so I lack a mousewheel, is there any way to set Tertiary back to default?