What do I need to do my electrical system in my dart.

Decent article for separating wiring by device:
Proper Race Car Wiring Principles - Davis Technologies

Decent chart for amp draw vs wire gauge, and some more wiring info:
Wiring 101: Basic Tips, Tricks & Tools for Wiring Your Vehicle

These may lead you down a rabbit hole, so don’t chase it too far, but info is always good. Have fun!