Indeed you need a bridgeboard or a card called Goldengate to activate these slots. Doing it this way you can use the
ISA.cards from the AMigaside if there are drivers for these cards available. Look at aminet for drivers.
or
You put in a industry "PC on a card" into one of the ISA-slots and then you have two independent computer in one box. Doing this you need a separte PSU for the ISA-PC. And keyboard Mouse etc.