Q: how can i activate my i phone 5 ? my apple id didn't work ??

What do you mean it "didn't work"? What is the message you're getting?

If you got the phone used, it's probably activation locked. Contact whoever you got it from. They will have to remove the lock.

It's activation locked. If you bought it used, contact whoever you got it from. If they can't or won't remove the lock, return it and get your money back. If they won't refund your money, turn it over to the police. There is no way to bypass the activation lock.

If you bought it new, take the phone and the original receipt to Apple to have the lock removed if you can't remember the account you originally set it up with.