@dth2
Here is a link to solve your problem.
The reason for the blank screen is that the install has installed the default graphics card driver (Nouveau). This does not support the later Nvidia cards (yet?)
Once you get to the desktop you need to install the Nvidia driver. Ubuntu now have tested various drivers so its better to use one of them rather than the drivers from Nvidia website.
Easiest way is in a terminal sudo ubuntu-drivers install.
Also the default for neon is to wayland. If that is a problem with some apps, then start it at the login screen with x11 (bottom left corner of the logon screen). If you do this it will then always boot to x11 until you change to wayland the same way at logon.
Edit:
Here is a link KDE GUI won't boot to another discussion with a bit more information for background.