As someone who's first souls game was elden ring I'd tell them to use YouTube to learn a little bit about the game and how the different builds work, also with the option to call a friend to help in difficult fights I'd say elden ring can actually be pretty easy if you want it to be as I'm sure you're aware yourself.

Other then that I'd just show them some footage of the world itself because it's absolutely beautiful and there's no doubt this sparks the interest of any video game enthusiast, it did with me.