Well I am going to go against the grain and say that I absolutely love it. 100k for that building is simply unfathomable to me.
The first thing is to go to the City Zoning Department and find out what it's allowable usage actually is. We can all give you weird and wonderful ideas about the fairy-tale fun park you can build there but you may not be allowed to do any of that.
Every City is different but I know in Miami they would never allow you to turn that into residential because each living unit must have a certain number of designated parking spaces. I would then look around and see if there is any vacant land very nearby that you can buy to be used for parking.
I am also wondering what, if any, heritage regulations apply to this building. Again, you may be very restricted in any renovations or improvements you want to do.
I would then have a professional building inspection done. As others have mentioned, the MEP might be extremely dated and costly to maintain.
After conducting the above due diligence, I would do market research and ascertain what kind of venues are in demand there. I'd like to know more about the local demographic, as that will weigh heavily on what you do with it.
I've always wanted to own a church. Message me if you want a partner!