What resources help newcomers learn the payments industry quickly?

tl;dr: there is no single place.

If you are new to this space, read payments related news. That would at the very least set the compass in the right direction. It may not make sense, but it will eventually.

Find out some of the companies you want to learn about, and follow their twitter, Instagram accounts, and especially their blogs & videos. You will learn a whole lot more from there. See if they have any uploaded white-papers or webinars they did.

Another great way is to have a nice RSS feed with the names and relevant keywords of all the terminologies etc. that you would like to keep abreast of. Put them in an RSS feed reader and read up on them.

You must understand, not everything will make sense on day one. Give it a couple of months (3–6) and everything will start to fit in and make sense to you.

Just don’t overwhelm yourself. Don’t go reading everything there is.