I don't recommend sharpening your knives and axes on this thing. Without proper experience and instruction, it is highly likely that you will ruin the heat treat on your blades and/ or remove way too much metal at one time. I would inspect, clean, and maintenance the thing. Then, with proper hearing, eye, and face protection run the thing and make sure it is safe and functional.
Use it for projects around the house for items that aren't necessarily going to be ruined by getting them hot. Use it to debur a freshly cut piece of metal, "file" things down that would otherwise take forever with a traditional hand file etc.
Always wear proper safety gear with these things and make sure you don't have any loose clothing or hair that could get caught up in the thing.
I highly recommend finding/ making some kind of a guard for the wheel itself and replacing the base plate it is attached to just for starters.
The absolute best thing would be to sell/ give it away to someone that knows what they're doing with fixing it up (if you don't) or doesn't care about their safety.
The thing doesn't look flat out non-serviceable, but it needs some work to be safe and convenient.