Born in Falmouth, Cornwall, Miller was a product of the Falmouth Town youth scheme playing mostly in midfield before being persuaded to take up goalkeeping in the Combination League team by then manager Keith Rashleigh as a 15 year old.
Miller, a native of Falmouth, Cornwall, started his football journey in the Falmouth Town youth system, initially focusing on midfield before transitioning to goalkeeping under the guidance of manager Keith Rashleigh at age 15.