If you aren't able to fix your power switch, portablizing probably isn't a good hobby to start with. You should try to learn on something easier (and cheaper), like LED modding some gameboys, maybe try to build your own controller for a NES or SNES, something along those lines. Once you become familiar with how power works, and wiring in general, come back to this. It'd be beyond easy to fix your power switch if you understood basic wiring.