I being 15 get all over the place! I recently have done most often:
Trowbridge-Westbury
Trowbridge-Exeter
Trowbridge-Cardiff
Trowbridge-Swindon
I bet you do!!! I really sympathise with you living there of all places! I had to live in Wiltshire's amazing county town between 8 and 19. My advice is to learn to drive ASAP and escape!