if i forget the APP ID and Password, how can i find back.
in some online shop, they confirm that they can help me if i pay for them
If you've forgotten your AppleID and password, then I'm afraid there is nothing you can do; you cannot get into your phone. And, the online shop is lying to you - there is no way to get around Apple's security.
If you remember the AppleID, you can re-set the password via Apple's website but if you've forgotten both, then I'm sorry, you are out of options.
Marilyn