Barcelona has an extensive public transportation system that includes buses, metro, and trains. The simplest option for visitors is to purchase a Hola Barcelona Travel Card, which provides unlimited access to all public transportation for a fixed cost. Taxis and ride-sharing services are also available, but can be costly compared to public transportation. Expect to spend €7-€10 for a one-way trip within the city.
If you have an extra day, consider taking a day trip to Montserrat, a nearby mountainside monastery with breathtaking views. Alternatively, if you're short on time, skip the Picasso Museum and spend more time exploring the Gothic Quarter.