I hope it is not too late. It would be very useful to know where you will move around, which cities you will visit, etc.
I only know in Madrid, Fotocasión (www.fotocasion.es) and in Bilbao (www.fotosamar.es). None of them show film in their catalogues but they have it. I know for sure that Foto Samar has Tri-X.
Anyway, have luck and welcome to Spain.