Your problem may differ from mine, but whenever I’ve been greeted with the command line in grub the solution has actually been in bios. I’ll leave you with my notes, which are a bit snarky after spending a lot of time trying to figure out hot to repair grub, when the solution was 3 clicks in bios:

"Inspiron won’t boot

Goes to the grub command prompt

Don’t fuck with that thing

Restart, F2 to get into bios

Change boot sequence to start the SSD first, not ubuntu

Reboot, itll do it a couple times, but should boot right into normal grub"

I hope your solution is the same

I’m sorry, what?..Oh, all I heard was that my linux home server is going to be running on new hardware in about a year and a half when all these used computers go on sale. 😁

I take any chance I can to drop a Chris Barnett link:

Ventoy

Oooh memories, I can’t remember the version number but mandrake 10 must have been close to my first linux distro!! …it.didn’t.go.well.

Dietpi is a nice little distro, especially when running it minimal without a GUI. Its added toolkits make farting around on the command line more comfortable