To install a printer in Ubuntu you should first have the necessary printer
drivers (CUPS, HPLIP and gutenprint). CUPS comes pre installed and I am not
sure about the others. Then it should detect the printer
and automatically install the printer. It does for my HP Photosmart in any
Linux distro, However, my Brother laser is another story since it is
networked through a print sharer. So I have to install it manually.

To manually install a printer you go to Printing in the menus of older
Ubuntu or in Dash just type Print and it should come up. Go to Add New
Printer and follow the prompts. Eventually it will come to a list
of printer manufacturers and you just choose from the list.

This is the first choice, preferable to getting it from the OEM. You can
install from a PPD if that is the file type you have See:
https://wiki.linuxfoundation.org/en/OpenPrinting/Database/PPDDocumentation

If it is a binary file from the OEM then you have to make it executable
before you can execute it. To do that open nautilus and right click on the
properties and check the box to make it executable. Now when you open it
you have the option to execute and it should install.