One of nine children and the only boy, Anderson grew up in Baton Rouge, Louisiana, before moving to New Orleans prior to seventh grade.[1] He attended Edna Karr High School in New Orleans where he initially planned to be a basketball player, before being convinced to focus on football after coaches told him of his potential.[1] As a sophomore, he was named first-team all-district.[1]
Anderson then helped Edna Karr to a 14–0 record and a win in the Division I state championship in 2024, posting 44 tackles, 15 tackles-for-loss (TFLs) and 10 sacks.[1][2] Anderson was a consensus first-team all-state selection for his performance.[3] As a senior in 2025, he helped Edna Karr to another 14–0 record and a state championship, having what USA Today described as "one of the most dominant seasons in recent Louisiana history".[4][5] In his high school career, he totaled over 200 tackles and 20 tackles-for-loss with six forced fumbles, earning All-District 9-5A honors in each of his three years on the football team.[6]
A five-star recruit, Anderson was ranked one of the top-30 prospects in the class of 2026, according to 247Sports composite rankings.[7] He committed to play college football for the LSU Tigers and signed with them in December 2025.[8]