New year, finally starting this.
What's the best recommended class for a newbie? The intro CGI seems to suggest the orc looking characters are the most invested narratively (?) at least.
You can respec trivially (100 gold cost, if you're diligent about looting things you'll have thousands of gold by halfway through act 1) so just pick whatever you want to RP as and make adjustments to your build down the line when you understand the systems better. The game isn't really that balanced, the best builds are jankfests that exploit obscure ability interactions via multiclassing. The only thing you can't change via respec is your race/origin, I would suggest either a custom origin or The Dark Urge (since all the other origins are party members anyway).
Two warnings:
1. Paladins need to stick to their oaths, and most of the oaths involve not killing innocent people, not behaving dishonorably, etc. If you do break your oath you become an oathbreaker paladin, which is sort of like a death knight/shadow knight class and is perfectly playable, but if you ever want to respec after that point (even just to rearrange your build while remaining a paladin) you have to pay a 1000 gold fee. I would avoid paladin as your first class for that reason, though if you really want to be a paladin apparently the Oath of Vengeance is a lot more lenient than the other two.
2. The Dark Urge is the "canon" storyline and has a lot of additional content, but some of that content will involve the unpredictable demise of valuable quest NPCs. I think it's the best way to play the game, but only pick this if you're OK with discovering in Act 3 that some super good item for your build is no longer available because you involuntarily murdered someone back in Act 1.
A couple more tips:
1. Save all unique gear, you never know when some item that you thought was useless will turn out to actually be really good due to some other item or ability you don't get for another 30 hours. You'll never be short on cash, just send any unique gear you're not using to your camp storage (you can do this in the menu, you don't have to actually go to camp).
2. I know I said above to just pick whatever class you want to RP as, and that is what you should do, but some of the classes are frankly redundant versions of other classes. If you want to be a big guy with a big sword who hits things pick fighter (battlemaster subclass) instead of barbarian. If you want to be a clever/skillful guy who shoots things from afar and picks locks pick bard (college of swords subclass) instead of rogue or ranger (edit: apparently ranger is actually good so disregard that part). If you want to be a mage do 2 levels in warlock (to get Eldritch Blast, Agonizing Blast, and Repelling Blast) and then multiclass to sorcerer for the rest of your levels - wizard is also a strong class but I find that it requires a lot more worrying about spell slot management, whereas sorlock can fall back on Eldritch Blast spam if you get caught in an unexpected encounter. All the other classes (cleric, druid, monk, paladin) are perfectly viable.
3. You can respec your party members, including changing their classes. Having a character with high charisma (bard, paladin, sorcerer, warlock) as your party's "face" is useful for passing deception/intimidation checks, so if you haven't picked one of those classes consider respecing a party member to serve as your diplomat.