Feb 15 - Feb 20 in Barcelona (R4R)

Hello everyone! I am 25M living in Paris and I am going to visit Barcelona from 15 to 20 February. Currently I have no idea of what to do in Barcelona and all the things that I should def cover. The only plan that I have made is to watch Barca's match on Feb 17 :) So can you guys please suggest me what should I do and where should I go as a solo traveler? Any dos and don'ts are also welcome!

Also, if you are free in those dates, I am open to meeting you! So hmu and we might be able to make some plans together in those dates!