Barcelona is probably the most accessible city of Spain. The capital of Catalonia is connected with every major city in Spain by the major highways. To the south it s connected to Valencia and Tarragona, to the west with Madrid and Zaragoza. While the northern highway leads to France and the rest of Europe.
Barcelona has excellent train connections, despite of the fact that there is no direct international connection with France. Spanish railway tracks are different then the ones in France so they can t connect. Though there are a lot of people from France using the train Paris to Barcelona. You will have to switch trains before you enter Spain. Travelling to Barcelona by train is one of the most popular ways for people from the west coming to the city.