Don't concern yourself with Ultimate right now, too many new players want to jump straight into Ults because they get told things like "UWU and UCoB are really easy now" and end up terrorizing groups by having absolutely no high end experience. They're still Ultimates even if they're easier than they were on content, and I wouldn't want to do them with someone who hasn't cleared a tier of Savage this expansion.

The newest EX (Zermous) is a great starting point for current content, the DPS check isn't too high and it has a lot of recoverability even if you die. My first clear of it had 6 deaths and that was going into it blind. There's really only one body check-ish mechanic and even that can be salvaged if people are willing to sacrifice themselves. Once you're comfortable with the newest EX, you can try jumping into the current Savage tier, Anabaseios. That's how I would recommend going about it.