*cough*Kerbal Space Program*cough* Seems like you're off to a good start. But: Real Solar System / Realism Overhaul? Are you nuts? Most people, let alone new players, never even touch it. It's very complicated, designed for those who really love rocket science, down to the nitty-gritty of fuel type balancing. And I don't know about the Steam thing, but I think that it means that you should copy your files to a separate directory as a backup. I don't use Steam for KSP. Other than that, hello, and Welcome!