Unfortunately no, at least not leagaly. :-( All Amiga OS versions are still under copyright. You will need to find out what OS the A500 needs. Usually it displays a picture of a disk with the OS version number below it. If it's OS 1.x or 2.x you'll need to try to find a copy at a local or on-line Amiga shop or
buy a copy from someone who doesn't need their Workbench disks anymore.