I just returned to Hearthstone after several years. Now I don’t understand how some new mechanics work. I know, that most mechanics are explained when you hover over a card. Some aren’t. For example: How do Drinks work? Is there a good guide, that explains all new mechanics?
The Wiki is very helpful for stuff like this. Here is the link to the new expansion. The new keywords are explained there as well.
Drinks are just spells that can be used 3 times.
The News page is also helpful.
I think the OP is specifically interested in the Keyword and Mechanics concept which is practically the main scripted mechanics of Hearthstone (e.g. “Battlecry”; “Charge”; “Discover”).
Google “Hearthstone Keyword and Mechanics” without the quotes; I see a couple of websites with full lists; not all are fully updated.