Hello!!! Welcome to dA! I hope you enjoy it here! ^^ If you have any question our doubt feel free to ask. I'll try my best to help
This place is big and it's normal to get a little bit lost when joining. Just to clear up some things:
Watchers are people who follow you (like followers on tumblr or subscribers on youtube).
You can watch other deviants as well, and when you watch someone you recieve notifications about new work, journals, critiques they make etc etc (you can edit this so you can recieve notifications about new works only, for example ^^)
You can collect art by favouriting it
You can also join Groups in dA. They are meant to bond users by a common interest and to give more exposure to deviant's works. You have many groups that are dedicated to everything art related, but some are only for a particular type of art, like traditional, or digital, or even writing. Just do a little search for what you want here.
Llamas are... well... they really don't have a purpose here xD they are just fun and users like to collect them! xD You can give out as many llamas as you wish, but only one per deviant. And you don't lose your own llamas when giving one to another person.
Daily Deviantions are daily features chosen each day by a select group of volunteer members. Usually daily deviations are particularly impressive or otherwise interesting enough artworks that volunteers consider that deserve being brought to the attention of the community . You can check DDs here.
Points are dA's money. You can "pay" some things with points, but many people use real money to buy prints, or other kind of stuff here on dA.
Core members are users who paid (in points or money) for a "special" membership. By becoming core you can access to some things that aren't available for non core members. You can check those advantages here.
Okay I hope this can help clearing up some questions. Hope you have fun!