There's a lot to explain there. I just gave you your first gift. See the little strawberry to the left under your name and info. That's from me. You can buy those for other people with points you gather from posting or from people posting on threads started by you, etc. You can buy yourself ribbons. I have two, my PCOS ribbon and my Pregnancy/Infant Loss ribbon.
You can go into your User CP (the botton is at the top of the screen) and click on options. Scroll down to the bottom until you see something that says "Mood" That's where you can add a mood thing. See where mine says persnickity right now. Some of them are even animated.
Your signature is also changed in the User CP. Click on signature and you can add pictures, though there are size limits. Some people put blinkies. Some link to their websites, etc. If you're looking for some cool blinkie sites I'll give you the links. I can give you the names of some ticker sites, too. You'll need a photo hosting account. Most people use
www.photobucket.com. It's free. I use a paid account b/c I use a lot since I have a couple of websites. You save your pictures in there and then you can use the IMG codes for your siggy. You don't need photobucket for tickers. They'll provide you with the codes you need.
If you have any more questions just let me know!