I can’t find my Apple ID for an iPad that I purchased 10 years ago and nobody’s been able to help me!

See if you can recover the ID/password. An iCloud e-mail address is an Apple ID. Use every email address you can think of.

Apple ID - How to find your Apple  -  

Apple ID - Find  -     

Other ways to find your Apple ID

You can check to see if you're signed in to the App Store, FaceTime, or Messages on your iPhone, iPad, iPod touch, or Mac, or check to see if you're signed in to iTunes for Windows on a PC. You can also go to iCloud.com or appleid.apple.com and see if your Apple ID prefills on the sign-in screen.   

If you forgot the Apple ID (iCloud) password, enter the Apple (iCloud) ID, and click Forgot Password. See if you can get a Rescue or Notification email option if necessary. Link to contact Apple Support at the end of the 2nd article.

Apple ID - Manage

Apple ID – Forgot Password  *      

Perhaps you may have someone known from that era

who could recollect what email address(es) you had?

Any other paid services such as an ISP, which offer

an email account in addition to internet service?

If you forgot your iPad passcode - Apple Support

//support.apple.com/en-us/HT211078

"If you can’t remember your passcode when you try again, you need

to use a computer to put your iPad in recovery mode. This process

deletes your data and settings, including your passcode, giving you

access to set up your iPad again. After you erase your iPad, you can

restore your data and settings from backup."

If you forgot your Apple ID password - Apple Support

[Your iPad may be too old, for this idea too.]

(Several short term ones, from webmail, I never used

for anything such as Apple ID; with few exceptions.

Usually mine, with those, were alias names..)

Wonder if there'd be a way to re-set the iPad w/o that?

Sometimes a fair idea is to write stuff down, in address

book; and make a private code out of those entries.

Seems so much has changed with newer ones; not so

much with older iPad/iPod security. ~ Not sure if Apple

could help you; with a proof of purchase, to reset that.

See this article and follow the steps provided to recover your lost Apple ID

How to use account recovery when you can’t reset your Apple ID password - Apple Support