Many projects do not actually require much knowledge about electricity. Despite what is learned in places like physics classes, it is almost never necessary to use Ohm's law to calculate voltage, resistance, and current in a circuit. Many of the components that you will use are really self-contained and just need to be hooked up properly. Really, it often boils down to reading specification sheets and documentation. The devices will say what voltage they need and how much current they will draw and all you have to do is make sure it is getting what it needs.