Thanks for the replies all. I've added friends and I'll be checking out the Discord channel. I strongly agree that it would be a very nice benefit to have an official feature, like a training room, to help new players in a friendly environment.
I'd also suggest creating your own decks and playing a bunch of games against Lord Rat (aka, the bot). It sometimes makes very stupid moves, but so what . . . your goal here is to learn the cards. And of course, when you play against the bot, he/she does not care if you take a bunch of time to review the cards, he'll grant every "undo" request without complaint
, and you can play him over and over, and he'll never say, "have to run, time for work"!!!! ;-)
On the old Making Fun site, there were campaigns, which were a great way to see all the cards, in various combinations. Here, you'll have to create the decks, which is a tiny bit of extra work. But you will be able to create exactly the deck, with the specific cards you want to learn, which was not possible at MF in the past.
Fortunately, the learning curve is very steep, so you will learn a lot, very fast. It only takes a game or two to understand almost every card, although subtle nuances will take much more experience . . . which is the joy of the game, of course.
p.s. My experience with Rachmaninoff has been very positive. He's a very advanced player, but also super-nice and friendly. Aside from him kicking my rear end in pretty much every game, I have no complaints about him. :-)