Garvin was a quarterback at Bradenton Southeast High, gaining 1,131 yards total offense as a senior (754 yards and 13 TDs passing and 377 yards and six TDs rushing) as the Seminoles went 13-1 and advanced to the state semifinals. As a junior, he concentrated on basketball, averaging 22.4 points earning second team Class 6A all-state honors. He played football and basketball as a sophomore; that year, Southeast won the state title on the hardwood. Garvin also was a sprinter on the track team.
As a true freshman, Garvin was the leading receiver at the University of Missouri, with 36 catches for 608 yards (16.9 avg.) and two scores, earning Big 12 newcomer of the year recognition. He started every game during the 1999 season, and caught five passes for 78 yards in 2000 before leaving the Tigers and enrolling at Manatee.