It’s complicated but it’s also very simple. Comics are written by lots of different people over decades. Lots of things don’t add up, even within specific continuities. If you are asking about continuity then chances are you don’t read comics and are thinking about starting and don’t know how to. The best advice for beginners is that continuity doesn’t matter. Start off by reading the highly recommended stories. There are lots of them. Wide varieties. Pick a character and see where it takes you. Yes, sometimes there will be references to the greater picture you don’t understand at first, but it likely won’t matter to the storyline you are reading. That’s the fun of comics, you discover your tastes and interests the more you read. One story or character can lead you to read more outside what you normally would. You discover which writers and artists you enjoy most. You read because you get hooked into all these elements and only a few weirdos get off on chasing continuity. It’s really not important. Just read something if you really want to learn about comics. People here can help guide you and fact check, but overall just read what makes you happy.
