Am I supposed to have a separate email for my iMac like a Mac email address or just one that I’ve been using for my iPhone?

Are you supposed to have your own Mac email address even though I have an iCloud email address? If so, what do I need to do in Laymans terms to create that account for my iMac since I don’t know what I’m doing I don’t want to ruin my computer in settings because I’ve been known to do things like that in the past, so I don’t mess with them. I know I learned to ask questions.