Joseph was born in Columbus, Ohio and grew up with two brothers, Zachary Philip "Zack" Joseph (also a singer) and Jay Thomas Joseph (a Twitch streamer), along with one sister named Madison Grace Brett. His mother, Kelly Joseph (née Stryker), was a math teacher in the Olentangy school district before being named Olentangy Orange High School's basketball coach in 2013.His father, Christopher Anthony "Chris" Joseph, was also a coach at Worthington Christian High School from 1996 to 2005, and is a former school principal.
From 2007 to 2013, Joseph uploaded short comedic skits and videos to a YouTube channel named slushieguys.The channel currently has over 124 thousand subscribers as of November 2018. After seeing a songwriter perform at a High Street club, he rejected an opportunity to play basketball at Otterbein University, along with a scholarship to the university. He began playing music after finding an old keyboard in his closet, a Christmas gift from his mother, and began mimicking radio melodies.From around 2007 to 2008, Joseph recorded a solo album titled No Phun Intended in his basement. It was later revealed that Thomas contributed guitar to several songs on the album.