OK, so I've read enough and played enough to realise how difficult it is for players to make money in game to buy the super cool toys that make the game more enjoyable. 

So to make super fast cash, you'd first need to buy the bow and a handful of arrows to start off with, or ASAP. It's a cheap purchase overall.

Your main target will be the Brachiosaurus. Try to score a contract before targeting them to maximise your income. (In fact, try to at least have a couple of good contracts before hunting anything, as a general rule.) There should be plenty of contracts that ask for two or more for a heap of cash. The only stipulation is that you'll be scoring a 100 percent integrity shot against them; this is where the bow comes into play.

So why the Brachiosaurus overall? They're big, hard to miss from a distance, and relatively slow-moving. They also have this habit of lining up perfectly towards you as they charge at you with the intent of stomping you into the ground, again relatively slow moving. LOL

When they're charging at you, they will be exposing their underbelly, which will give you the perfect opportunity to aim for the vital organs—the heart and lungs—for that perfect 100 percent integrity kill.

Just make sure to stop firing arrows at them once it looks like they're about to flee; you certainly don't want to spoil that 100 percent integrity score by firing into its spine or tail. Just be patient; when they're fleeing, they're about to drop and die.

Unfortunately for you, you may have noticed how this game has that really annoying habit of throwing carnivores your way in order to make life hell for the hunt. 

A tried and tested method I've noticed to avoid these annoying obstacles is by using the water to avoid getting eaten. Most of these carnivores never took swimming lessons, so running along the edge of a lake or the beach so you can duck back into the water is a great way to get rid of them.

Important note! This tactic will not work against the Spinosauers; they can swim and swim very well. So running into the water to avoid them will equal certain death as your weapons are taken away for the swimming effect.

The two best locations for hunting these long-neck punching bags and avoiding being someone else's next meal are:

1) The lake at the center of the map is the largest lake in the game, so it's a bit hard to miss, but I'll circle it in red anyway.

and 

2) The beachfront, just north of the Ranger's cabin.

Both of these two locations are hot spots for the Brachiosaurus and provide you with enough opportunity to run into the water for protection. 

Sometimes your contracts or the dinosaurs themselves will dry up from time to time, so it is best to fast-travel between these two locations to keep them fresh and the money flowing.

I personally fast-travel to the radio tower, to the ranger cabin, and back, depending on the number of dinos running around. This way, you won't have to walk extreme distances, and you can rack up the cash fast. 

Now you'll have to initially find these locations; however, I've made it really easy for you with my screen shot. As a new player, you would have noticed some fast, one-way travel locations. There is one just north of the lake that's easy enough to get to. In order to move between the other radio tower and Ranger's cabin with ease, I've used a black arrow to indicate its location.

If you are going to the radio tower, first be mindful of the steep ledge around the mountain. There is an easy enough trail to help you move down and back up again to avoid fall damage. I've circled the location on the map in black. 

Caution: These two locations are frequented by Tyrannosaurus a lot, so it's always a good idea to take out a contract on them in order to find out where they are at all times. Or just listen out for their bloodcurdling roars. 

I hope this helps, and I personally would have loved to read this guide at the start of my adventures or misadventures. LOL

If you have another way of making money the easy way, let me know in the comments below. Cheers.