I'm 12, and I very much enjoy this game. I have landed bases on both Kerbin moon, and gone to Eve and Duna. I'm planning a Joolian trip next. I think it is mainly a question of your interests and capabilities, as I have always been interested in space, and science in general. If you want to do this kind of stuff, you can, and I think KSP is probably the best spaceflight simulator there is, with a ton of mods, a large, helpful community, and it being fun for any skill level. You can make a cannon and see how far a kerbal can be shot, or plann missions like NASA does.