Do you mean you have found games cartridges? If so they are probably
Commodore 64 and not Commodore Amiga 500.
The A500 used 3.5" floppy disks, the drives you have are probably
floppy drives not hard drives. A hard drive would be internal (unless
it plugged into the left side of the A500) and would be pretty fast
loading games etc.
An A500 these days is not the best machine for multimedia or
productivity but it is a veritable games machine!
You could try asking someone for Stunt Car Racer or First Samurai
amongst the other 4,000 or so games for Amiga!
The more experienced users out there probably make use of their A500's
for all manner of useful things - maybe an IRC chat machine or e-mail
collection. Whilst only having the gaming power of a Megadrive the
A500 is far more versatile. Why not try getting a genlock and putting
titles onto your favourite home videos!
:-D