Issue installing NVIDIA Graphic Drivers for RTX a5000 laptop gpu on Ubuntu 18.04 OS

Hi, I have a Dell Inspiron 7760 laptop with nvidia rtx a5000 laptop gpu in it. I have installed ubuntu 18.04.6 LTS standalone OS in it. The mentioned OS doesnt come with proprietery graphic drivers for rtx a5000 gpu, so i have externally downloaded the drivers for rtx a5000 gpu and installed it. It got successfully installed but i am not able to boot or login after the installation, its showing blank screen,can you guide on this issue.

The stock kernel 5.4 that comes with Ubuntu 18.04 is too old to driver your intel igpu. Please either upgrade to 20.04 or install a newer kernel from ppa:
Please uninstall the runfile driver and use the one from Software&Updates after updating the system. If it’s not available, you can add the graphics drivers ppa: