Hi again,
I have some progress with this. I am testing this small scale with the 74HC595 and one digit common anode LEDs. I followed the Freenove tutorial on this and it works
As it happens, the idea is to lead the four anodes to pins 4-7 on the Arduino. But if I am to supply 9 volts to the big displays, how does that happen?
Do I need to have four transistors, one for each anode, to act as a switch for the anodes?
Again, I hope I am not making a fool of myself for asking this, but I am a n00b still and would love some more advice, for which I am always grateful.