Day 1 ladder group levelling etiquette?

Hi, I've played ladder before but only ever levelled solo. I kind of want to join a group this time around but I'm unsure what the etiquette/strategy is when speeding through the game? Do people split up to do different quests? Are certain optional quests skipped and some others done as a group? Appreciate any guidance on this as I'd love to group level but don't want to be an asshole out of ignorance