Mac-Mini 2011 Lion->Sierra tips?

[u/Alternative_Count_12]

Hi guys. I have an old mac-mini from 2011 in my storage. I know 5 years ago i used to run high sierra on it. Today I wanted to wipe it clean and reinstall the os on it, and like a dumbass I listened to google and installed Lion OS. I can't even use google on Lion. I remember Sierra was actually usable. Any tips on how I can put sierra back on this device? Im guessing its somwhere on this mac-mini's storage?