I never wear makeup and I'm going to a wedding. Help.

I have worn makeup twice in my life, not because I don't like the look of it but just because whenever I try to wear it I seem to mess it up and look silly.

In about ten days I'm a guest at a wedding and my skin is currently breaking out and leaves a lot to be desired. I was just going to go ahead and accept that I look fine the way I am but my mother suggested I at least wear concealer so...

Concealer help, anyone? I'm pretty pale save for the pinkness from my (sporadic) acne and dark circles under my eyes. I just want to look decent in any photos and show the bride that I made an effort. I intend to ask at Sephora and Mecca Maxima tomorrow but figured you guys wouldn't be trying to sell me something for the sake of selling me something.

My budget is ~$40. Thanks in advance. ♥

ETA: Here's a current picture if it helps get an idea of where my skin tone/texture is at.