powermac from year 2000

It is a gift.
With boot camp i can't work, that is for mac os 10.4 or later.
I know almost nothing about the mac.
The machiene is running mac os 9.2, had 64mb ram, now with 256md extra.
The shape from the side is lake a triangle.
The mac had integrated crt screen and speakers.
He had standard 64mb ram, now with an 256mb ram extra.
What i like to know is how i can enter the systemsettings, like on a pc the bios settings.
How ca i boot from the cd or control the boot options.
How can i install a newer version of mac and linux on the same disk?
Wkat version can the old mac run?

I just discovered that the powermac had a hard disk from maxtor, 10 gig.
I will install linux on the machine.
When i disconnect the disk, the machine boot from mij cd.
I need to change the bootsequens.
How can i enter the settings.

Note: I have not the original keyboard or mouse, i use a usb keyboard for a pc with windows.

THere is no Bios,

but you will be able to load Ubuntu for PowerPC on that mac