[2023] Im a new LoR player and I'm having a hard time building a good deck for standard mode

I started playing LoR a month ago, at first it was good and I could play PvP with the starter decks until I could make my own deck but suddenly rotation happened and all of my starter decks were useless. After the rotation I tried to make a new decks with my limited resources, but it wasn't enough, and I could only make 3 copies of Samira, and that was it. She's my only viable champion :( So now I have to wait 3 weeks to get 3 champion wild cards from weekly chests so I can finally build my first deck after 2 month of playing?

In the other card game I'm playing (gwent) you can mill the cards you dont want to create a card that you need but there isn't such mechanism in LoR.

I was wondering if there is any other way to get some champion wild cards or shards besides the weekly chests or buying them?