I enjoyed many a bullfight when I lived in Spain and was able to watch a few famous matadors such as Paquirri, Paco Camino, Antonio Ordonez, Curro Romero, and D. Fermin Bohorquez (who fought on horseback) while there. One thing about bull fights is you either love them or hate them, there is little middle ground. I witnessed many a bull be killed, but also a number of matadors being gored. On only a couple occasions did I witness a bull walk out of the ring. I last attended a fight, in Madrid, in 2007. If going, the seats are concrete bench. Buy seats in the “sombra” (shade). That will keep you out of the sun for at least part of the fight. There are 6 fights, each lasting about 20 minutes, and each matador fights 2 bulls.
We purchased the bullfight tickets the day of the fight from one of the many kiosk type stands right at the bullring. To get there, we took the metro to the Ventas stop.
If the bullfight museum is at the bullring, you could probably visit on the day of the fight, but not visit those parts of it that access the ring directly (i.e., the ring itself, corrals, Chapel) because of the fight taking place the same day.