There are a lot of things going on in this kingdom, and if you don't know all the cards, you're going to have a hard time absorbing all the lessons. I think lesson 1 is that attacks are often the key to the game, so when you're looking at the cards, look at attacks first (iso conveniently puts a red dot next to them)! If you don't see a good way of dealing with an attack, you should probably get it, asap, and try to play it as much as possible. Here, taking this approach, you would probably want to open Potion/Silver, and then focus on buying Familiars and Minions, which in addition to attacking, cycle your deck around to play your Familiar(s) more often.