Whats up with the house and the magical memory wave? I don't really understand what happened. Like i get that everybody got their memories back but how does this come into context with the world we live in? Is this a post-apocalyptic future or what?
Yes. it is a post apocalyptic future, one in which there have been many apocalypses in their past. Reading the second book, there are a few lines of the ritual song that told of the past that implied that Baltimore, Toronto, and Bogota were all destroyed so long ago that their names were forgotten. Even Christianity was forgotten with just the cross viewed as a curiosity that once had meaning but that meaning now long forgotten.
The house Jonas ends up at was part of Village, which features in the third book, "Messenger". The house itself wasn't specifically shown as it had been about seven years later.
The memory wave was just a way to show how the community began to heal itself, something hinted at in the third book.