Barcelona has an efficient public transportation system, which includes buses, metro, and tram. A T-10 ticket can be a good option, allowing you to take up to 10 trips, for €11.35. Taxis and ride-sharing companies such as Uber and Cabify are also available, but expect to pay much higher rates, especially in touristy areas. Consider walking or renting a bike if you want to explore the city center to get closer to the culture and architecture of the city.
If you have more time, consider a day trip outside the city, for example, to the famous Penedès Wine Region, Sitges town or the monastery of Montserrat. If you have less time, choose any three of your preferred district from above 7 days and experience everything in a smaller amount of period. Don't miss out on trying some of the delicious Catalan food and drink, such as paella, cava, and tapas. Take some time to learn some useful Spanish phrases, as it can be difficult to get around in just English. Lastly, before travelling in any country or city, always carry a facemask and hand sanitizer with you to remain safe and sanitize due to the covid-19 havoc.