When installing vinyl plank flooring, it is generally not necessary to cut off the tongue of the first row. The tongue and groove system is designed to interlock the planks together, providing stability and preventing them from separating over time. By leaving the tongue intact on the first row, you create a secure connection with the subsequent rows, ensuring that your flooring remains in place. Furthermore, cutting off the tongue may lead to gaps or misalignment between planks, compromising the overall appearance and functionality of your floor.