Good luck with your audition! How are you learning a Cockney accent? (By videos/recordings? I've never tried to learn an accent.)

(Happy early birthday! :D Hugs)

Think about what a birthday is - it's like passing a landmark on a road, there's nothing magical about it. It doesn't really affect who you are, how you change and what's in your future*, because you're still steering. :)  All you have to do is to look for the ways you can improve and work at them patiently.  And sometimes we do change in bad ways, and then as we become aware of it, we just have to steer for the better again (we all make mistakes, after all), and no one whould expect anything more of you, should they?

*Except for legal demarcations, like driving, voting, etc :P

As far as nervousness goes... I took my test for my second degree black belt earlier this month, and I somehow kept myself from getting nervous until the morning of, when i was completely tense X) When we were all lined up to begin, one of the masters who was going to be evaluating us gave us a speech wherein he told us not to worry - he told us that at one of his tests a long time ago, he found that he was nervous about whether he would pass and how well he would do, and finally he realized that it didn't make so much difference to him, because whether he passed or not he would still be back at the training studio for the next class, still working hard.  And when he said it I relaxed and decided to have fun at the test and do my best, and I did.  (I think I passed, but I won't find out for a few months.)

Auditioning might not seem like exactly the same, but maybe it's a similar thing - if you don't get a callback, what will you do then?  You might have heard it, but it's truly not the end of the journey... it's just a crossroads. :)  Go at it to have fun and give it your best!  Whether you get the part you want or not, you won't have need for regret.

...poke!

Wow. I have zero disipline, and I could never do anything like a audition on my B day.

And calm down. I don't think you become a zombie when you turn twelve. You turn into a smarter person! 

I can't help you much with the auditions because I've personally never been in one, but learning an accent isn't too hard, especially when all the words are still in English. If you can't get it perfect by the end of the week, I'm sure no one will blame you.

As for the birthday, turning twelve isn't so bad, and I completely with what Oregano said. Don't worry about it! (Ack, I turned into Xephos for a second) 

Happy early birthday Icy! Being 12 is amazing, you'll love it! 

And, don't worry about your audition, I'm sure you'll do great. Just before you audition, take a deep breath, tell yourself you're not nervous, and walk in confidently. And remember to HAVE FUN!!! That's the most important part about auditioning. If you don't get in, you can always rememember that you had fun, and maybe even try again later.  

I hoped that helped, I've never really auditioned for anything except for in my homeschool group, but always remember that we're here for you Icy, and we will help you in any way possible.