Bootstrap row and col explanation

Answer 1

Bootstrap has a own Grid-System, which allows you up to 12 columns. From the docu:

Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or viewport size increases.

It has a reason why it is just 12, and not as many as you want to have. This article describes it perfectly well: The Subtle Magic Behind Why the Bootstrap 3 Grid Works

After reading this, you are perfectly ready to work with Bootstraps grid system in the way its meant to be.