compiling – boot [HELP] i messed up my PC

Hi today i downloaded the angband game and decided to compile it myself so i extracted the files and ran these commands on my terminal

./autogen.sh 
./configure --with-no-install
sudo checkinstall

After that checkinstall failed to make a .deb package i deleted the whole folder containing all of the stuff.( I know i shouldn’t have messed with things i don’t know) And my pc froze then i restarted my pc and this screen appeared . even when i chose linux-recovery from the boot menu this screen appeared again. My pc literally will not boot. 🙁
Can someone help me how to fix it or even teach me how to backup my files so i can install ubuntu again ??