Hey, where can i start?

Hello, a pleasure.

Warhammer has always seemed like an expensive hobby to me, but I came across some kits at over 50% off, and of course, how could I resist? So I looked around to see which one caught my eye, and besides the Sororitas, I saw these beautiful mechanical beings.

I don't know anything about WH40K, but I'd like to learn more, especially about this faction because it's the one I bought.

Is there any site/channel you recommend to learn about their lore? (Also, one to learn how to play)

Aside from that, can you tell me your favorite things about the Adeptus? What do you like most? Is it fun to play with them? (And is it complicated?)

Thank you so much for reading and taking your time.