Hello Tsugu and welcome to recreatu! :D
I agree, when I first started a couple years ago I was overwhelmed as well. How you play the game really depends on your interests. For instance, some people like to train their pets while other like to set goals such as collecting every color of every creatu or maybe just a certain species of creatu.
There are numerous way to make tu, which is this gams currency. You can do quests, sell items if you're a merchant, or sell pets if you're a rancher.
Here are a few guides to help you get started:
FAQ
Shoutbox Spam Guide
Staff List
Advertising dos and don'ts
Beginners Guide
How to be a rancher
I really hope to see you around a lot and if you have any further questions feel free to send me a rmail. :D