´Hi pbedouk,
welcome to these forums! I'd like to help you, but I need some information first:
When starting 0 A.D., did you navigate to the Main menue and click on Settings followed by Hotkeys?
Did you double click on the entry you like to change and did the window with the four fields open?
Did you click on one of these fields and pressed the desired key long enough to have it logged in?
Did you click on the button Accept (window closes)?
Did you click on Save and leave the Hotkey setting menue?
I'm looking forward reading from you and hope your problem will be solved soon.
Best wishes,
Obelix