How would I install a different copy of linux on a old laptop?

TLDR; I am trying to install a GUI version of Linux on an old laptop with Ubuntu Server already installed, but get a grub error when I boot. How can I get past this problem. error: file '/boot/grub/i386-pc/normal.mod' not found. Entering rescue mode... Current Linux Version: Ubuntu Server 22.04.3 LTS New OS: Linux Mint 21.2 64 bit (disk image on USB) I installed Ubuntu Server 22.04.3 LTS on my old laptop. The intention was to back up all my photos onto a home server. Now, I want to install a Desktop version of Linux on it. I have tried to research and ask some some friends, but I am just not knowledgeable enough about the subject to understand. What can I do/investigate to move forward? Please treat me like a 7 year old, when I see 'grub' I think of an insect in the ground.