Natural Collection works very well.
Miss Sporty has a great one that helps act on spots as well.
Maybelline
Revlon!
I use stick concealers,because I don't really get dark shadows under my eyes, but I find that liquid concealers help that.

But it ight be different on your skin... basically the most important thing is that you use a concealer that matches your skin tone.

If it is slightly uneven use a foundation that matches your skin tone to even it up.

Just make sure you wash it all off before you go to bed, but I'm sure you know that... yeah?,

Hope that helps?
I'm 13 by the way.