I'm going to Argentina soon and I found a really good site for learning/practicing voseo. It's called www.voseospanish.com
¡Nice to meet you! I´m from Argentina and I made a guide with that, here

May be It will help you, I have a question: ¿Where are you from? ¿What part of Argentina are you going (The city or the capital)?

Welcome [Y] You´ll be great here!
I plan on going to Buenos Aires. I'd like to go to Patagonia but it seems prohibitively expensive. Any tips for getting there on the cheap?
you must use the train, but they are not very well. or used the camping this is cheap and well in the summer