Technically there are expansions.
There’s the starter set, bashing vs finesse, which is just two specs, intended to help you learn the game.
Then there’s the core set, red vs green, three specs vs three specs. Both of these (starter and core) l come with tokens and game boards (although I think they’re different game boards but don’t quote me on that). The core set also comes with red and green binders.
Then there are two expansions: white vs purple and black vs blue. These don’t come with tokens or game boards, only cards.
The deluxe set contains bashing, finesse, green, red, blue, purple, white, and black. It has one set of tokens (so buying an extra starter set or something might not be a bad idea if you ever want to play with more than two players at a time). It has six binders, one for each colour. It has two very nice playmats and also some regular play boards. It also includes the special map cards, which are a bit weird and crazy. We’ve got a tournament of those going on right now.
Lastly, the best way to get into it is to play! You can play right here on the forums. If I remembered where the rulebook was I’d link it to you, but I can link you codexcarddb.com a website with the cards for reference. So hang around, play a game. It’s good fun.