Llanwrtyd is on the Heart of Wales Railway line and has its own small station in the town centre. There are also regular bus services running between Brecon and Llandovery and Builth Wells to Llanwrtyd. For up to date information, have a look at Traveline Cymru. There are also plenty of local taxi firms that will be happy to help you reach your destination.
Llanwrtyd has a selection of small, traditional shops with larger supermarkets located in Llandovery, about 10 miles away.