multiple apple email addresses

Please check -> iCloud: About your @icloud.com, @me.com, and @mac.com email addresses

iCloud: About your @icloud.com, @me.com, and @mac.com email addresses - Apple Support

can I delete the other 2 and why are they there

If you have delete it, it is no longer valid, it simply no longer exists and it no longer works.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

Understand and control the personal information that you store with Apple

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

You might need additional Apple ID addresses in some cases.

Have look at this related article:

About your Apple ID email addresses - Apple Support