Nobody can tell why you can't print from a computer because you haven't described what you're doing or what happens afterward.
In general, to print from a computer you go to the printer manufacturer's website and lookup their instructions for installing the printer. They may ask that you install software first. In any case, the easiest and most straightforward method to print from a computer is to the connect it to the printer with a USB cable. But you have to follow the printer manufacturer's instructions.