I just looked through the pictures and I'm really at a loss as to what it would take to make it attractive. You mentioned creating an event center to hold weddings. Why would anybody want to get married there? What would it cost you to make it attractive to the point couples would want to have their wedding pictures taken in front of that building? As mentioned, that roof line is a huge failure on every count. Tearing off the roof and rebuilding a new roof will also require significant work on the walls. They would have to be removed too, and then whatever you build, you are relying on the block to be structural. I don't know if it is or isn't, but it is ugly and would have to be covered in rock or brick or something to make it attractive. That's $10 a square foot in just materials for decent looking fake rock.
Road going in and out needs to be two lanes for events. Where will you park 100 cars? How big is the septic system? Will it handle hundreds of people? What size meter is there to the property? You'll need at least 400 amps because of the HVAC system. Is it on city water or well water? If it's a well, how is the water quality?
If you are wanting to start a business holding weddings and events, you need to create a Business Plan first. There are a lot of sources out there to help you do this, the SBA was my favorite source. Set up a meeting and talk to somebody there. The guy I met gave me a bunch of information, and pointed out where I was off target in my Business Plan. Figuring out what it will cost to open up, what you will make in your five year projections, and what your profits should be is needed before you can know what you can spend on anything.
As for this building, I still feel the best thing to do is walk away.