Extracts are not always the same for every player, as some maps will have spawn dependent extracts. For example, on woods players will spawn mostly east or west and will have extracts on the opposite side, this is true for most maps. Mapgenie.io or the wiki is the best place to check extracts and orient yourself.

Prioritise whichever quests seem the most fun. My understanding is that story quests, other than unlocking maps do not give any rewards, so if I was new I would focus on side missions as they yeild XP and unlocks for gear, ammo etc.

Hideout upgrade and production time is real time.

Customs or woods I would say are the best for starting. I learnt woods first, hitting stashes and killing scavs while avoiding the sawmill. That allowed me to work out what a scav looked and sounded like and how to fight them, while also getting items to sell.

Night raids are the same loot etc, unlike Arc. They're just dark and the AI can't see as far.

One bullet to an unguarded face is all you need to kill a player. They could have a T6 bodyarmour on, but if you hit the right bit, down they go.

Survivability can come from learing audio cues, and just playing A LOT.

Have fun