New to WoW, should I play Classic first before Forever launches?

Never played WoW before, but I'm excited about World of Warcraft: Forever and want to jump in at launch (or the beta if I grab a pre-purchase pack). Since Forever is built on vanilla-era systems, I'm trying to figure out the best way to learn the game beforehand.

A few questions for people who've been playing a while:

• Is it worth leveling a character in Classic Era first to get a feel for vanilla-style mechanics, or is that a waste of time since Forever will have its own new zones/quests anyway?
• Would I actually be better off starting on Retail instead, since I've read it has a better tutorial/onboarding experience for total newcomers?
• If Classic Era is the move, does faction/race choice matter much for a first-timer, or should I just pick whatever looks fun?

Not trying to rush to end-game or anything just want to understand the core gameplay loop before Forever drops so I'm not completely lost on day one. Appreciate any advice.