How do I upgrade to a new version of Android?
You'll need a version that is specifically designed for your device that has all the drivers necessary to operate your specific hardware configuration.  If no one has compiled a ROM for it you'd have to build one yourself from scratch.  You best bet finding a 2.2 ROM for you device is over at the XDA Developers forum.  Then even if you're able to load 2.2, Flash is going to be a whole different story.  I had the Viewsonic g-tablet with Froyo (which as a Tegra2 Processor) but the Flash that I side-loaded wouldn't work at all.  Force close after force close.  Then with my newest tab, the Archos 70, even after they released 2.2 it was a while before anyone could find a version of Flash that would run without force closing and it still operates poorly.  I suspect you're going to be disappointed with your Flash experience, especially if you have cheap hardware.