You are just not going to find much online. You will need to network, in person, when you get here. I recommend going to art openings, especially open studios, and talking to artists. You should be able to find a spot, but you have to plug into the grapevine. A good website for whats up is Ramona, but realistically, the art scene in BA, like the music scene, is pretty last minute- very few press releases, very little advance notice. You need to get on facebook- everything happens on facebook- and at the least, follow the hipper galleries, and then trace the artist's named to their personal pages, and see whats up. There are great free public spaces that show adventurous art, and not too many private galleries. this list is a good starting point- https://turismo.buenosaires.gob.ar/en/atractivo/300pm-art-galleries-villa-crespo-and-palermo
if you just google "galerias de arte villa crespo" you get a good dozen interesting space. If you could ever catch him, Lolo, at UV Studios, knows everybody and everything happening.
I would not worry too much about taking art back- best is in checked luggage, assuming its not framed in gilt frames, most likely they will never notice it. I transport my own work back and forth from time to time, never a mention. If, as Steve does, you had a hundred or more rolled canvases, and you tried to take a big cardboard tube on with fifty of them, maybe- but in general, they are looking to catch national patrimony, not wacky avante garde modern art.
also, I would heartily recommend that, in addition to doing lots of your own work, you go out a lot and see shows, openings, live music, and the scene in general. Its amazing, wide, deep, and really really fun. Almost nobody expects to become the next international art star- instead, they live life for the moment, and have a hella good time. Dont expect to sleep a lot. October-January are prime months for all kinds of art and music and performance happenings. And, as an architect, you will see amazing buildings every time you walk anywhere, in every barrio.