During my Cyber Security studies, I am using Kali Linux to learn the operating system and the commands I need. I maintain this list as a reference for my research and what I have learned.
Find files from the terminal
Run sudo updatedb.
Search for files with wallpaper in the filename and a .png extension: locate *wallpaper*.png.
I use xxd with the file path and pipe its output to head to see the first 10 lines. The file command provides a more readable description of the file type.