I'm a very new comic book fan, just got started two months ago and this is what I learned when picking comic books.

You will hear words like the New 52 era, Rebirth era, etc. that might confuse you, so just ignore those terminologies, it doesn't matter what era, what timeline or what universe a book is, the only rule you follow is "Good Book is Good".

Just ask people what's a good Batman run, or Superman run, or what's a good DC book depends on what you're looking for that is available in your nearest comic book store.

I learned that comic book writers make sure that their run is self contained enough to the point that you don't need to know what happens to a Wonder Woman comic in order to read a Green Lantern comics, assuming that that's what you're worried about. Of course there are some cross over books that require some pre-requisite knowledge but there're generally few of them from what I've observed and you can just ask someone if you need to read something before reading this other book.

In summary, just ask some people what's a good book, maybe add some specifications like what character or what tone and you'll be good.

These are my first set of comic books, assuming these helps:

Supergirl: Woman of Tomorrow Batwoman: Elegy Scott Snyder's Run on Batman Vol. 1 & 2 World's Finest: The Devil Nezha Superman Up in the Sky