Welcome, just to tell you. You can use the emotes, but use them in the right place at the right time.
Cookie Monster: Sarcastic Post
Cookie: Don't use this one
Panda: Used as puppy dog eyes to beg for something or pretend to be cute
Ice cream: Personally never used it, but its used to stimulate food
EDIT: You'll also be called an alt(alternate account for banned user)
Using the Cookie is perfectly fine.
For example, you are in the Gallery or Add-On board.
Wow, that's pretty good. 9/10 
Use the Cookie symbol to show your appreciation or approval.
Using any of the emotes is perfectly fine. It's just the act of using them in moderation. You don't want to post loads of them just for the sake of it. It appears to be spammy to do so and it isn't looked well upon.
Welcome to the Forums! It's great to have another new member, and especially one who is capable of picking up on some of the trends we have here.
There is some form of unwritten rules/forum ettiquette on here. It might help you sail through Forum life more easily if you follow them, but ultimately, all that matters is that you read and follow the Forum rules.
Make sure you've read them all and know where they apply. If you get confused or aren't sure then feel free to ask. We'd much rather you ask about the rules than you unknowingly break them. And in general, not knowing the rules isn't an excuse for breaking them.
But, beyond that, it's lovely to have a nice new member and I hope you enjoy your time on these forums and have fun. Any questions at all then just ask away. Looking forward to seeing you around the place!