I have just installed my Ardunio Uno on my Model Railroad. There are 5 different projects all running at the same time and using Millis for delay times and running on the same script. It works perfectly. I have only used the Digital outputs. My question is this.
Can I now use the Analog as outputs to create more project?
Using the same Millis Code as with the Digital will I be able to just add them to the one script as they all must run at the same time?
I suspect that you are thinking that analogWrite() is for use with the pins marked "An" (e.g., A0, A1) on your Arduino board. This is not correct. analogWrite() can only be used with the pins on the board that have PWM (or DAC on certain Arduino boards), as documented on this page:
If you want to use the pins marked An as regular digital outputs, just use then with digitalWrite() or digitalRead(). For example:
This is not a scold. It's advice. All the answers to your questions so far, are on the first page of the Arduino documentation. Please always look there first, it will save you a lot of time.