Although this a free-to-play game it relies heavily on monetisation with four individual currency/resource systems. These break down as follows:
Coins
These are earned and awarded regularly during gameplay.
Dino Bucks
This is the premium currency of the game and is used for park upgrades and speeding up timers. Dino Bucks can be purchased with real money and used to buy coins or food outright. You can also get Dino Bucks by completing special offers through Tapjoy.
Food
The dinosurs need to eat food to become big and strong.
DNA
This is needed to hach new dinosaurs, you can earn DNA by selling off dinosaurs or watching video adverts.
Card Packs
Jurassic World offers card packs similar to those used in the Pokemon games and enables you to pick up currency, bonus missions, and rare dinosaur species in exchange for real money. Every six hours you will get one free 'Mystery' pack which will allow you to play for a decent amount of time but during that time you will be bombarded with prompts to buy expensive packs which range in price from $5 to $50.
Unfortunately to evolve and level up your dinosaurs so that they are able to compete will either involve spending weeks of grinding to earn the required currency or putting your hand in your pocket and spending real money to unlock rare dinosaurs which are expensive but will have a chance against anything the game throws at them straight away.