Hi there and welcome to IcePets! Caring for the pets is pretty simple - food items raise hunger, and toys raise mood. You should get a newbie pack with some of each, but you can also get lots of cheap items from the main shops if you need them. Right now, there isn't a major penalty or benefit tied in to these stats, so don't stress too much!
The real fun of the game is in the community, the collections, and exploring everything. Most of the site can be accessed through the arcade page, so I'd recommend starting there!
Here is the node, you who hate change and fear revolution. Keep these two squatting men apart; make them hate, fear, suspect each other. Here is the anlage of the thing you fear. This is the zygote. For here "I have lost my land" is changed; a cell is split and from its splitting grows the thing you hate—"We lost our land." The danger is here, for two men are not as lonely and perplexed as one. And from this first "we" there grows a still more dangerous thing: "I have a little food" plus "I have none." If from this problem the sum is "We have a little food," the thing is on its way, the movement has direction.