How to recover my old Apple ID?

1.

Depending on what you did with your 'old' Apple ID.

If you have deleted it, it is no longer valid, it simply no longer exists and it no longer works.

To understand about a deleted Apple ID, see the Apple articles below:

How to delete your Apple ID account

How to delete your Apple ID account – Apple Support (UK)

-> Once your account has been deleted, Apple can't reopen or reactivate your account or restore your data.

Understand and control the personal information that you store with Apple

Understand and control the personal information that you store with Apple - Apple Support

2.

If you still know that 'old' 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

Start with Apple's advice in

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

If you forgot your Apple ID password - Apple Support