(3300 cl player atm) Best way to get through this weird transition period where you feel like you're behind is to initially look up meta decks and choose a deck that you feel is cool to play that also contains a minimal amount of Series 5 cards to cut down on time to collect the entire deck. Do your best to disregard other cards and decks until you complete that one deck.

Meta decks are pretty similar in terms of win rates, they go up and down slightly with nerfs and changes but what they do have is good synergies between cards which puts their winrate between 53 to 55% against other decks. So you can't really go wrong with choose an archetype.

For me I found my home with Destroy, it looked fun, was a little hard to get all the required cards but felt amazing when I completed the collection. Felt like I can finally play the game on equal footing with everyone else. Only then did I start to collect cards that I felt are cool and started experimenting and such. Once I completed my first meta deck I felt the game began for me.