The above link will take you through to the NHS site which will enable you to put in your post code and find the nearest Pharmacy near where ever you are staying in England.

You will find a Pharmacy in most towns on Dartmoor, Yelverton, Tavistock, Mortonhampstead, Bovey Tracy, Okehampton to name a few, you will also find in-house pharmacies in large superstores such as Tesco and Morrisons most village stores and garages will be able to sell Paracetamol, cough medicine and general needs products.