If you forgot your Apple ID and password, navigate My Apple ID on Apple's official website, and click Reset Your Password. On the page that appears, click Forgot your Apple ID, enter information such as your first name, last name and your email address in the required fields, and click Next.
If you prefer using email as the authentication method, choose Email Authentication, and click Next. Immediately after this, open your email, locate the email from Apple Support, open it, and click on the Reset Now link. Since the reset link expires three hours after the arrival of this email, you have to use it within that time. On the password reset page that appears under your email address, enter your new password, re-enter it for confirmation, and click Reset Password. If successful, a message confirming the reset of the password displays on the screen.
If you prefer security questions to email authentication, choose Answer Security Questions, and click Next. Enter your birth date, click Next, enter the answers to the security questions you set when signing up for your Apple ID, and click Next. If the information is valid, enter your new password in the page that appears, and click Reset Password.