ICloud – Apple ID – Email Address Change

I am thoroughly confused by the Apple ID, Email Address, User Name, iCloud conurbation it is to me an almost impenetrable mess. The best answer I have found here is below and I would appreciate some clarification. What I want to do is change the @outlook address I was forced to use to set up Apple ID to an @icloud address. The clarification I need is in the original answer below, the reason is I am conbverting an 86 year old man converting from Microsoft to his first iMac 21 last week! and I need to keep it very simple, trying to explain why he needs a microsoft email address to access his Apple ID is beyond my powers – and his. So I want to set it up with an @icloud address – please help 😎

The answer I found that explains all except the crucial bits is below in quotes, question mixed in for clarity and context.

"Sign out of iCloud, the iTunes & App store, FaceTime, Find My Friends, Find My iPhone,and iMessage on each device that uses your Apple ID."

OK no problem I don't have any of that,the iMac 21 is the only Apple he has.

"Sign in to your Apple ID account page."

Fine used @outlook address I had to set up specially to get a Apple ID

"In the Account section, click Edit > Change Email Address. Enter the email address you want to use as your Apple ID."

I want to use an i-Cloud address – how and where do I get an i-cloud address set up?

"A verification code will be sent to your new email address."

Yeah brilliant what new address how can I use an email address (@icloud) I have not set up and have no password or login for?

"Enter the verification code from the email into the fields provided and start using your updated Apple ID. Didn't get the email?"

Er no – I have no icloud address yet to get a verification on?

You see the reason for my utter confusion – I thought Linux could be a bit tricky but this bit of Apple Lore is a total mystery seems I am missing a fundamental fact here, does an icloud address get set up automatically and how do I access the thing???. TIA Jonah