That I am less sure of, I haven't done this in a while. Officeworks would be a reasonably decent option to get them printed on the spot. They're usually pretty helpful at the counter.

Next level would be something like Minuteman Press, bring the files in on a USB and they can talk you through the size and options (glossy/matte, borderless, paper weight etc.). Best option depends on if the art you purchased is photographic, illustrative etc.

If you want really high quality prints you're gonna want to talk to a Fine Art Printer about getting a giclée (inkjet) print. This is the most expensive option but will always give the best results and they'll get the best out of your purchase.