If you want to use a floppy disk on an Amiga, first you need to make sure your floppy drive is working, so test with a known good disk.
Second, don't bother trying to use a PC unless you have a Catweasel. Use an Amiga; a PC can do it but it's very complicated and you need two disk drives.
Thirdly, use Double Density disks, not High Density. It may work on certain HD disks but don't be surprised if it fails to format; even if it does format, expect to lose data. Sometimes you get lucky, and an HD disk will work for a while, but never trust data to one. HD disks require a stronger magnetic field than DD disks, so your old A500 drive probably can't magnetise the surface enough.
You shouldn't have any trouble if you follow that. There's nothing special about Amiga disks or Amiga drives, it's the controller that's special.