I have done the part of creating a bootable usb for dual booting ubuntu 20.04 LTS through rufus But after restarting the laptop and choosing the usb ,I am getting a grub menu saying minimalist bash like editing is suported,with the grub menu
Can anyone please guide me how to proceed for the installation?
I am having nvme ssd.

1. Test it on another computer if possible.
2. Did you verify the download of Ubuntu with an md5 or sha checksum? That info is on their site.
3. Did you get any errors when using rufus to write to the usb? If so, what were they.
4. Have you booted usb's from this computer before? Do you have multiple usb ports? Try them all.

The grub bootloader wasn't properly installed. Someone might be able to help if you answer the above questions and also indicate if you currently have any other operating system on the laptop and indicating specifically, what it is and which version. You might try rufus or use some other similar software. It's possible you might be able to boot it from the grub prompt but we'll need a lot more info to start. When you get that message, do see: grub> or something else?

rufus has a dd function that sometimes works better.