Barcelona is considered by a lot as skatepark city because nearly all of the streets and squares are skatable. In fact, the Raval neighbourhood where MACBA is has a polished floor and sidewalks that you can comfortably skate on, for example to Paral-lel. It's recommended to visit the other parks like Universitat, which is very close by along with Paral-lel and Sants. Other known spots are Forum, Besos, Fondo and Montbau among others but these are a little further away.
If you want a break from skating you can also go to see plenty of beautiful places. Some of the most visited are Güell Park, Casa Batlló, Camp Nou, the Boquería market and the Ramblas. The famous Sagrada Familia Basilica is also relatively close to MACBA.