I belong to Rvillage camping club. It ts free and has an all that you download and sign up.
There are different clubs within the platform and there is something for everybody.
If you have a question around RVing or anything, they have so many people that are engineers there that they can answer any question you have. I find it a great resource.
Here is a simple diagram of a 12volt battery configuration for your typical RV.
I thought it was pretty good. Next figure Explains parallel and series wiring.
The next chart explains the state of charge when reading your screens.
Try saying that 3 times fast.