Difficulty Following Chess

I am greatly struggling as a fan of chess to follow all of the main tournaments and to make sense of the scoring systems and so on and so forth as they go on.

The Grand Chess Tour is young, but they have recently changed the scoring system such that the results of a given tournament do not directly correspond to the results of the whole tour overall. This was not made obvious in any way, and I have not really been able to follow the tournament due to this. It took me a very long time to find out.

These sorts of things are common in chess. Overall, it is an insular game, where the ins and outs of tournaments seem to be known only to those who are involved with it in some way. It doesn't reach out to spectators, and is bad for the game. There is no centralised information source, or anything of the sort. It makes me want to stop watching the game all-together sometimes.

Can anyone explain to me how the Grand Chess Tour works? What on earth is a wildcard? What are round-robin tournaments? Why are some players not in every tournament? (Magnus, for example, is not in the Saint Louis Rapid & Blitz tournament). How exactly does the scoring system work? These unanswered questions stop me from actually enjoying what is happening on the chess board. It's very frustrating and annoying.

Thanks for your help.