Simplify the following text for a Grade 8 native English-speaking person.
Original: As a teenager , David-Lloyd joined the Gwent Young People 's Theatre in Abergavenny and The Dolman Youth Theatre in Newport , where he was a contemporary of the actor Matthew Woodyatt and the singer Nia Lynn .
Simplified: When he was a teenager , Gareth joined the Gwent Young People 's Theatre in Abergavenny and The Dolman Youth Theatre in Newport .