lol, its fine. On my first portable I was just like this. You can use standard wire or any ribbon cable wire for everything switches, soldering on the board, screen wires, and screen power.
The only wire that has to be non standard like 18 guage are the first wires coming from the battery. Meaning the first positive and negative wire coming form the battery. I am not 100% sure about this next part, but its to make sure that you are getting your full voltage and your max current, which is MAh that can come out of your battery.