Badges of Dorkdom by Theo Hodges

Inspired by Isekai transporting a future college dropout into a fantasy realm, Badges of Dorkdom is his mission to defend Earth by the glory of Fireballs. This time, the System picked on the wrong dork. 

Books in the Series:

Dreadlord Wizard

Dreadfortress

DreadWar

Box set - Amazon | Audible