computer starts with grub after installation - what should I do

I just installed LinuxCNC on a ZOTAC ZBOX
However, after completion it boots into grub
I'm quite inexperienced with Linux
What should I do next?

Normally GRUB is not displayed, but it will be displayed for several seconds then move on to boot the PC if there are other kernels or operating systems on that PC.
Did you try to press enter?
Post a picture here on this forum if it does not go any further.

thank you for the quick reply

it stops at the grub prompt.
even after waiting a long time it doesn't continue automatically.
there are no other kernels or OS - I told the installer to use the whole disk and use a single partition.
pressing enter doesn't help

I typed ls to get a list of volumes - see the picture

 

Yeah, that.
In BIOS, find and disable the UEFI, set the boot options to Legacy, and disable "secure boot".
In some cases this is called CMS, so try with it disabled and enabled.
The bad thing is you might have to install again after changing those settings.
-
When you boot from USB, press F9 or F12 or whatever your PC has to select a bootable device, then choose the USB in Legacy mode, not in UEFI.

thanks for the help.
I now got it to boot into Debian, however I had to take some major detours with bad/wrong partition tables, replacing the SSD, and so on. For some reason it now only works with uefi enabled...
Not sure wether to leave it at that or try more stuff

thanks again

If it works, leave it as is.
I am sure Andy did a lot of testing with UEFI and it works in most cases with it, just some BIOS implementations are very, very wrong. I have a small laptop/tablet HP X2 Elite that refuses to boot anything over Mint19.3, i have tried everything possible under the sun, even did separate partitioning for everything, EFI included, it just gets to a blank screen.
Everything boots and works properly from USB.
But i like the damn thing, it can run Mesa boards all day long through a USB to Ethernet dongle!