Staying alive, the basics.
Don't stop moving.
You got a kill, you're feeling good, now it's time to see what lovely loot you can get from their sack (Giggity). BLAM! You're dead. What happened? You were stood still. Always maintain movement when you're looting, even when you're hiding. The community favourite is to crouch and bob about while crouching. It makes you a much harder target to 2tap and gives you a chance to get eyes on your attacker, to get into cover, heal and get some shots back on them.
Bleeding and healing.
If you got shot check to see if you're bleeding, you will bleed out if you don't stop the flow. You have a choice between Bandages (craftable and lootable from dead players), a Medpack (lootable) or a Procoagulant (craftable and in airdrops). If you're critically low health there may not be enough time to put on that Medpack, this is where a Procoagulant is ideal as it halts the bleeding with one application, but a few bandages are adequate and much faster than the Medpack. Spam those bandages on to build up some health so you can't be one shot, now apply that Medpack.
Wear a helmet.
Obvious right? You can carry more than one in Z1BR though, so make sure you have at least one spare, because lucky shot or not, you'll lose the one you're wearing in a fight. All that lovely loot you picked up could all be lost to just one shot to the head if you're not wearing a helmet.
Protect your chest.
Okay, you can 2tap an enemy in the head, or 1tap if you got your hands on the sniper or they're not wearing a helmet, but you can kill with body shots and don't underestimate how fast your enemy can shoot. You need some body armour.
The ultimate is the 'lammy', a bullet proof vest, capable of taking a few shots. You'll currently find these in some airdrops with some other treats, including the sniper early on, if you're lucky. Everyone in spotting distance will know where that airdrop landed though, so this is a risky way to get some armour. Worth it, but risky. But don't stand there waiting to open it, keep bobbing about and be a tricky target. In theory you could carry a spare if you're greedy but you'll need to abandon A LOT of loot to be able to. Sneaky way is to pop one in your car, if you have a car.
Alternatively you could sport a lovely Makeshift. The wonders of a broken helmet, a torn up Military Backpack and some duct tape. A cheap and cheerful way to help you stay alive. You can craft them when you need one, and you always will, plus you can easily carry extra. Sadly one shot and they're gone. You'll want to be keeping a supply of ingredients to hand as you progress through a game, much like you'll be looting ammo and helmets. It's a good idea to craft a spare so you can quickly switch while in cover during a fight.
Another obvious one. But you need to be careful. Losing your toes loses your life! Taking cover behind vehicles can still leave parts of your body exposed, so be mindful what your enemy is shooting at when you're in cover, they may see something of you that you didn't know was exposed.
Reload your weapons, heal damage taken, replace a destroyed helmet and mess with your inventory while in cover, it helps keep you alive. You'll be surprised how many people choose the Rambo route of wandering through the battlefield or standing in the open, contemplating how awesome their loot is, or how epic that last fight was.
Paranoia saves lives.
Z1BR has free look. Use it. Use it a lot!
Crouching behind a rock or a tree watching a fight ahead of you? Let them fight it out right? Maybe you'll take out the loser for an easy kill. You better be free-looking behind you in all directions because someone is watching you, waiting for you make your move and that's when they'll kill you.
Maybe you're moving through an open area to get to the next safe zone, but it's okay because there's no one around. You looked around, scoped out the area, it's fine, time to go. Were you free-looking while running? Oh well you won't know about the player behind you, silently zipping along in his car. No it's not a Tesla, they just turned the engine off after building up momentum and now they're floating up behind you. Aaaaand now your dead.
Knowables of throwables.
Explosions, flames and weird green clouds are cool right? Got you covered there with Grenades, Molotovs and the very toxic Gas Grenade, but there are other handy throwables out there that can help to keep you alive. The flash bang needs no explanation, it goes BANG and has a flash. They won't see you coming, or where you ran off to.
But you also have a Smoke Grenade. So much more than a mass of smoke, this can extinguish a deployed Molotov. You can of course use it to create cover in an open space, but you throw it at a player shooting at you from a higher ridge to hinder their advantage. It's also an essential tool when going for an airdrop or looting players, throw one at your feet when you get there and you'll have lovely cover while you loot.
Check the obvious.
It's easy to forget about the obvious things in the heat of the battle, or once you've dispensed on that enemy. Check the obvious. Are you wearing a helmet? Are you bleeding? Is another playing moving in on you? Are your guns loaded? Do you have armour? Are you even safe from the next gas circle? Always check the obvious.
Stay out of the gas.
Speaking of the obvious, stay out of the gas. Yeah thanks Dom, hadn't thought of that. Trust me, it's so easy to forget exactly where you are in relation to the next circle of gas verses safety. If you don't have a vehicle you're more likely to have a big problem of trying to heal the damage from the gas, while trying to reach safety. If you don't have a vehicle you could aid your chances by wearing work boots or Conveys, which will increase your running speed helping you reach safety that bit faster. Running with your guns away will also make you run a bit faster, you can't shoot that gas anyway right.
You'll discover different things for yourself as you play more and more. This guide is based on the mistakes I've seen new players make, so hopefully this will help keep you alive a little longer and get you on your way to that first glorious win. Good luck and GGs.