Hello and welcome to the forum 
If you have more than one problem it is better to create a thread for each issue.
I would address the Nvidia driver issue first.
Could you try this command in terminal?
sudo ubuntu-drivers autoinstall && sudo reboot
If this does not solve your issue, here's a member written tutorial regarding how to manually install Nvidia drivers:
There are 2 different methods.
The original tutorial by @Michel will give you the latest driver while @boldos method will give you a driver from PPA.
[edit]
I changed the title of this thread for clarification