The Stand question

You will be fine. It's not too scary or violent or inappropriate.

I envy you reading it for the first time!

Enjoy

If you've read other Stephen King books then the Stand isn't going to make you lose any sleep to nightmares. (Might lose some staying up late to try and finish it) Great book. Enjoy!

I was your age when I read it. If you're a good strong reader you'll enjoy it. If you have trouble keeping track of what's happening when your reading then it may be difficult to follow and you'll need to really concentrate on it.

I would say it depends on whether or not you can discuss it with your parents or another trusted adult. There are some very adult themes in it. When I was a juvenile, I was forbade to read Stephen King. If your parent/s are ok with it, then yes, if they are not, or don't know, I would urge you to make sure you have someone to talk to about the book first.

I think if you understand it; its OK, but In my opinion the book would be a little hard for you to understand. You might understand the actual words, but putting the big picture on it and understanding all the innuendos; situations behind the characters. It is an excellent book though.
There was a great mini series on The Stand. I think it was in the 1990's. I wouldn't mention it if it detracted from the book in any way, but it didn't.

Is there sex?

I mean you can, but I´m not sure he´ll understand.

I would have liked it as an eleven year old :)

Well, besides the gruesome deaths, the sex descriptions (including rape and other borderline non consensual acts), the occasional crude language, the philosophical overarching themes... yeah, sure, why not. 11 is the new 16 after all, someone told me.

Ask your parents.