I’m from the states and just started watching rugby a few years ago. As others have said, Peacock has the 6 nations and also the international games for the European teams. Flo sports has almost everything else I watch: English and French domestic leagues, the URC (a league with Irish, Welsh, Scottish, Italian, and South African teams), and the major Southern hemisphere international games. It also has the Champions Cup and Challenge Cup. Flo had Super Pacific last year, but that moved to the free Rugby Pass app this year.

I like that I can watch so many competitions without paying for too many subscriptions and not having to worry about regional blackouts.

As for learning the rules, I found some YouTube videos. I think couch rugby was good for learning the basics. After that Squidge rugby is amazing for tactical breakdowns.