Hello, for some reasons, I not log into my Ipad

To unlock your iPad, follow the steps described in the Apple article:

(< iOS 15.2) If you’ve forgotten your iPad passcode

If you’ve forgotten your iPad passcode – Apple Support (UK)

• If you don't have a computer and you can't borrow one, you need to go to an Apple Retail Store or Apple Authorized Service Provider for help.

(iPadOS 15.2 and newer) you don’t need to have a computer  -> If you see an iPhone or iPad unavailable message or Security Lockout screen

If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

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Have you forgotten your Apple ID?, Check your Apple ID via your email box, see this Apple article: If you forgot your Apple ID

If you forgot your Apple ID email address or phone number - Apple Support                  

OR see -> Having trouble signing in?

https://iforgot.apple.com/password/verify/appleid

Have you forgotten your Apple ID password? -> See this Apple article: If you forgot your Apple ID password

If you forgot your Apple ID password - Apple Support

Then see this Apple article: What to do after you change your Apple ID or password

What to do after you change your Apple ID or password - Apple Support

B T W:

You are sign in here .  .  .  with your Apple ID & Password.

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password deleteappsyou use to sign in, as well as the contact, payment, and security details that you use with Apple.

You can’t merge multiple Apple ID accounts.

See the following Apple articles

Sign in with your Apple ID -> Sign in with your Apple ID - Apple Support

Manage and use your Apple ID -> Manage and use your Apple ID – Apple Support (UK)