I don't know of any courses, but watching all youtube videos by "Pine hollow auto diagnostics" will take you well through most parts; that guy specialises in vehicle electronic faults & explains everything he does.
"Basic vehicle electronics" like ignition modules? Or "infotainment systems" or like the LIN bus (or CAN bus controlling all the communications of lighting, sensors, HMI, etc? Which part of the car are you interested in?
Note that some require factory software and laptop (or custom computer). Some require factory diagnostic equipment available only to dealers (or authorized service centers).