I do not know Gallium, so I have very little to say about that.
Windows software can be run using Wine. It is a Windows emulator, and there is no guarantee it will work with CSP. Alternatively you could check for alternatives that run natively on Linux (Gallium). Krita? Inkscape?
Make no mistake, your journey into Linux will be riddled with obstacles, as it is not close to Windows at all. Inform yourself, learn, ask questions. But most of all: have fun!