Hi and welcome
Your comeback resembles mine, I bought an A600 about 6 years ago just to be able to play some gamnes I played when I was young but I ended up owning a bunch of Amigas and my interest for the AmigaOS, hardware and software became and new hobby and passion.
To prep that harddrive you have and to install the Amiga OS you need a set of workbench disks.
The Workbench version to use depends on what kickstart version you have.
