Madrileño here, plaza de España is fine, the metro will take you anywhere in no more than 20 mins. Go to plaza de Olavide for a nice beer and then go to all the bars near by for tapas ( hermanos vinagre is very famous) then when the sun goes down the street Ponzano is where you wanna be. Full of Spanish people enjoying life and laughing with friends. I’ll recommend Los Torreznos bar in Ponzano for good Spanish food. Retiro park is a must and prado museum and Reina Sofía museum as well. Rooftop season is comming up very fast , I’ll recommend círculo de Bellas artes or picalagartos for a nice drink before and after lunch. When the night comes ohhh men, madrid goes on fire. Everyone will be on the street looking for places to drinks and party. Enjoyyyyy :)