Lemonier played his prep ball at Hialeah High School in Hialeah, Florida. It’s unclear what he did following his graduation in 2015 as I can’t find anything about his time playing football at Ventura College in 2017. He played just a single season in Ventura, collecting 79 tackles, 18.5 tackles-for-loss, 8.5 sacks, and one interception. He helped Ventura to their 16th conference title in school history and was named the Defensive Player of the Year in the conference.
His success did not stop after leaving the JUCO ranks, however. Lemonier went on to record 13.5 tackles-for-loss and 10 sacks to go along with 55 tackles and two forced fumbles in his first season at Liberty.