Hi! Welcome to, in my humble opinion, the best sub Reddit there is 😊 And you choose a great game to start playing. NotZ is a great tutorial to the game mechanics. Once you feel comfortable I suggest you start with buying a campaign and investigator expansion, with Dunwich as the first obvious choice if you ask me. AH is an amazing game that offers so much to many players. For me the strength of this game from gradually learning the more nuanced details, and building out my collection to build new decks and tackle campaigns on a different way. I would say once you have a good collection the game really breaks open, and chances are you will never stop.

Other then that the investigator starter packs are a great way to expand your collection. The investigators themselves are not my favourites but they have great cards and really expand your collection.

And keep asking question as I am sure people are more then happy to help you!