Questions using this tag should involve a 3D printer that is manufactured by Monoprice and branded by the name MP Select Mini 3D Printer v1/v2/pro.
This cantilever, low price, printer design not only comes fully assembled, it has already been calibrated at the factory. All you have to do is perform a quick check to verify that the print bed is still leveled, then load a model from the included micro SD card, load some filament, and start printing the loaded model.