Travelling to Newport from London can take you 4 - 5 hours depending on what time you leave, and the traffic. A few stopping off places will help especially when travelling with small children. Access from Cardiff is around 2 hours. It is best to stick to the main roads once past Carmarthen, as sat navs can often lead you either around in circles or up dead-end farm tracks. From Carmarthen you can either go west to St Clares, then Haverfordwest, Fishguard and on to Newport. Almost the same amount of time, the journey north from Carmarthen to Newcastle Emlyn is on a slightly smaller A road. There is a big Tescos in Cardigan if you come this second way which you may wish to stop off at depending on your arrival time. They will also deliver groceries if you order online in advance. The closest railway is in Fishguard.