For what is worth, I will give a few hints for those venturing to England for the first time. I will not clam that I know everything, or for that matter, much of anything.
The rail system, even after 15 years of using it is still largely a mystery to me. I know booking in advance is the best way to insure that you won't have to cash in your life savings for a simple few hours ride. I've had the best luck with the rail passes, which can only be purchased before you leave home. They are for a number of trips within a set period of time. There are several options on rides, and time they encompass. They are good for the airport shuttles.
There are few universal truths about any mode of public transportation.
1) It will be full to overflowing.
2) Someone will be sitting in the seat you have reserved.
3) Do not assume anything. Weekends are when construction is performed, so you could end up on a bus for part of your journey.
4) The English people are kind and courteous, but on public transportation it is every man for themselves, and especially when traveling to a match.
The trick to enjoying your holiday is to look at these minor inconviences as part of the adventure. Just be flexible.
One time when departing the train in St. Bees, I went to the wrong end of the train to exit. The damn door would not open, and the train was about to depart. The resulting sprint to the other end of the car, carrying full gear, probably resulted in several injuries to those seated on the aisles.
My several C2C walks have been among the highlights of my life. If you don't mind I'll share a few other experiences at a later date.