How to set up parallel port in Debian

In a terminal:
sudo lspci -v
and
sudo dmesg | grep par
Post the results of those two lines here.

Firstly, you don't really need to set the port up with Debian. LinuxCNC uses its own driver, so you just need to tell LinuxCNC the port address.

Actually, you often don't even have to do that, telling LinuxCNC to connect to the first parallel port that it finds (index number 0) is typically enough.

Do you see the p-port with lspci? If you do then it probably isn't at the 0x738 address (which is typically a motherboard port)

Can you show the output of "lspci -vv" and "cat /proc/ioports"

You can select the text in a terminal and right click to copy it, then paste it here.