How to start and is this game for me?

I am a fan of ASOIAF, and have played a Warhammer in the past. I never played competitively or anything like that, I just played with my dad and a few friends, and that was mostly with the starter set, but with other models that I bought as well. How hard are the rules to learn, and would it be okay for casual fun. If so, where should I start? Thanks for any responses!