Meh, don't beat yourself about for being a newbie, we all were once.
The point system works like this, every post you make gives you two points, if someone rates you, you get more points. And also, people can donate points to you as can you to others.
Now why do you need credits, I hear you ask (you might be asking it). Well it's simple, go here
, and you'll find a whole wealth of things you can buy with your credits (most of which need a whole loada them, sorry).
Of course, this isn't a reason to spam (and don't be fooled with the "add glow to username" thing, I didn't like it, but then again, you might).
So have fun.