Hi @Rylan,
try the following (or at least try it), the terminal command (Ctrl + Alt + t) is as follows:
sudo apt install nvidia-driver-390
This is on the assumption it will work for you??????. 
For reference, see also:
Hi @Rylan,
try the following (or at least try it), the terminal command (Ctrl + Alt + t) is as follows:
sudo apt install nvidia-driver-390
This is on the assumption it will work for you??????.
For reference, see also: