Beauty: Starting from scratch (Could'ee spare some help for a newb?)?

So, I know absolutely NOTHING about beauty or fashion, and up until right now, I didn't really care. However, for circumstances that shall remain unknown, I'm going to attempt to update my look.
This is me: http://hphotos-snc3.fbcdn0o0net/hs171.snc3/19838_225675591357_737086357_3055399_2439276_n.jpg

As you can see, I have a real problem with dark circles under my eyes. I use REALLY cheap makeup, so the concealer is basically crap. >_<

Makeup:
What do I use? What colors would work for me? Any suggestions for cheap-but-not-trashy-makeup?

Hair:
I've never blow dried my hair of my own volition in my life. How do I do it? (Keep in mind I have extremely thick hair) I own a straightener, and I can sorta use it. I'm just really bad at it.

Skin:
I use Proactive for acne, so that's no big deal… Should I get a tan? Any skin care tips you'd like to share? I'm a big fan of natural stuff (usually involving eggs xD )

Clothes:
Yeah, totally clueless here. I… I still wear culottes. *hangs head in shame* I have a deep love (and two pairs xD ) of striped socks. Is there any way I can wear these without looking like a dork?
I'm 98 lbs, and 5'2", small… urm… "up top", and 15 years old. I have NO idea what clothes look good on that.

Weight loss:
I train every Monday at the YMCA, but I could afford to drop a few pounds. However, I don't have the dedication or desire to develop an eating disorder. Any suggestions on how I can do this? (Note: I do use a few of the non-destructive tips from pro-ana websites.)

So, there's like 50 million questions for you. -_- If you can't answer them all, that's a-okay. I'm just somewhat desperate here…