When we were in Spain, we'd come back to our room sometimes and watch game shows. For the most part, the vocabulary was limited enough that between DH and me with our middle-school Spanish and, in my case, enough other European languages to give me grammar and cognates, we could understand enough to enjoy the shows and maybe pick up on a bit of the slang.
You should be able to find a slang dictionary, too - obviously there's no substitute for immersion, but for me, having spent a grand total of one day in France, my French slang dictionary is hugely helpful in reading online forums.
Speed comes from what you put behind you. - Judi Ketteler