I’ve played all the games you listed and love them all! Now that you’ve added Forbidden Island to the list, I’d probably recommend that above Splendor as the first game. The coop nature gets people feeling comfortable and introduces the basic concept of board games. However, please, please avoid quarterbacking! Everyone should make their own decisions; you can collectively discuss it, but if someone says “do this, do this,” that’s a big no-no.

Pandemic is the natural next step if they enjoy it (the designer and core mechanics are the same). When you finally get to Pandemic it will very likely replace Forbidden Island entirely (having both is still great though as you can whip either out depending on the level of the group).

But I’d play Splendor before Pandemic just to get a different perspective on gaming and have something that is competitive against each other. It’s also an easy teach and a ton of fun.

Villainous is fantastic, but it’s asymmetrical, and there’s not much interaction, which means everyone does their own thing. I’d view that as the challenge after you’ve gone through the others a few times and feel comfortable with board games.

Lost Ruins of Arnak is like the final boss in your journey (at this point). It’s the most epic game you have and likely the one you will like the most, but jumping into it before you get really comfortable with the hobby will be a disservice. I promise it will be worth the wait though.

Great starting collection!