If you want somebody to print digital snaps the way you would do at home with an inkjet printer and the right sort of paper then your local copy shop ought to be able to do the job.
If you need something for a presentation, an exhibition or a gift etc., you probably need a photo lab. There are several labs in and around Foto Club Buenos Aires at Hipólito Yrigoyen 834 - just google Laboritorio Fotográfico Hipólito Yrigoyen for specifics. Several have been there for decades and still have the capability to process wet film and print from negatives as well as producing images from digital files.
Many of the big, yellow Kodak signs are nowadays just historical artefacts but some of those shops still work in photography. Check them out and see. One that definitely was still going last year was a couple of blocks away from Museo Fotográfico Simik in Chacarita and another was in Avenida San Martin at around the 2000 mark on the opposite side of the street to the big Coto, however its opening hours always seemed to be a little -erme- unreliable.