General Hints and Tips
After the prologue, the resort can be pretty much explored to your heart's content. This walkthrough will only assist you in finding collectables and performing quests. I won't dictate what you need to do step by step as this won't make your game any more enjoyable.
Quests can be tracked. Aside from the obvious red flag marker on the map, you'll even get to see white dots lined up to show you the path in your mini-map. You don't have to worry since all characters share the same quests. Just refer to this walkthrough for additional help.
Fast Travel Exploit
You can basically use the 'Load Last Checkpoint' trick to get by faster, especially if you're just doing continuous quests. Take note that YOU SHOULD NOT use this especially if part of a main/sidequest includes collecting something and delivering it back to the questgiver; otherwise, you'll lose the item you collected and you'll have to redo the whole process again. Watch the video below to learn how to do it. This will save you A LOT of time.
Fast Travel Exploit
You can restore a bit of your health by drinking numerous scattered energy drinks and eating snacks. These recovery items re-spawn over time. You can't stock up healing items, only medkits. It is a good habit to keep a lookout for these since you won't know when you'll need a quick drink to save your butt.
Don't just swing your weapon haphazardly; if it doesn't connect, you're open for the biting. A good way to deal with fast, aggressive (normal) zombies will be kicking them. This will stop them on their tracks, giving you more than enough time to decapitate them or crack their heads open. Kicking can also be used with dealing with hordes of zombies to keep your composure and give you some breathing space. By jumping and kicking, you can easily knock down infected and walkers with ease, leaving them open for you to stomp.
Materials and Workbenches
Workbenches are essential to keep your weapons in top shape. As such, make it a habit to scour every searchable containers, luggage, cabinet you come across with. Modified weapons sport some really impressive base stats and additional effects normal weapons don't have so make sure you're always carrying one. If you happen to find a merchant selling some uncommon materials, make sure to buy a good number of them so you won't have problems creating the mods that need them.
Pick up almost everything that you come across with. Fortunately, only weapons, grenades, medkits and alcohol count towards your inventory limit. Miscellaneous items (materials and mods) don't count to your limit so there should be no reason for you for not picking them up.
Keep Your Weapons in Top Shape
You must remember that restoring a completely destroyed weapon is MUCH more expensive than maintaining it. As such, always keep your (main) weapons in top shape. It will be a hassle if you'll find yourself unable to afford the repair cost when you direly need it.
Look out for 'resupply points'
These are the places where you can find lots of recovery items such as drinks and food, as well vending machines (even better). There are several of these in the resort and in the city so remember their locations. In the jungle, you'll find these in front of stone idols as offerings. They may save you when you're in a pinch.