Hi Amy...and welcome to the site.
I had the pleasure of meeting Amy recently and she told me about her "free" bus and showed me photos of the full Budweiser wrap it's got. We both agreed that there's no such thing as a free bus.
Amy had seen the FB groups but didn't know about Skoolie.net so I told her she was much more likely to get actual help and experienced input here...as Flattracker already demonstrated.
So...Amy, tell us lots more about that engine and the issues and what your plans are for the bus (will you be driving all over the country or just moving it occasionally?). I think you mentioned that it wasn't running when you got it, but you did get it to the point where your son could drive it? Did I remember that right? Tell us more and someone here can help with diagnostics and input on the engine issue. Can it be saved? Let's see.
Almost any glass shop...doesn't have to be an auto glass shop...can get you a piece of tempered safety glass the size you need for your side window. There are also online sources, too, and I've used a few of those. Once you get the broken one out, and measure it, finding someone to cut and temper a replacement is usually pretty easy and not very pricey.
As far as wrap removal goes, I've never done that so can't offer any input. I look forward to seeing what others say on that...because I like learning here too.
Anyway, again...welcome. Kara and I enjoyed meeting you and we look forward to seeing you back out this way again someday...in your bus!