Welcome to amiga.org :-)
The easiest way would be to open up the amiga and see if the hard drive is there. You also might want to take a look at the battery, as it tends to leak after such a long time and the acid often ends up killing the amiga. You safely remove that battery, as it is only used for keeping the clock afaik. If you really need the clock to keep its time, then you can get a replacement battery for cheap.
I hope you will be happy with your amiga :-)