Changing my Apple account - How to carry over contacts, notes etc?

My reason for the change is that I can't change the primary iCloud email that is associated with the account, stated by Apple employees. There isn't enough purchases etc associated with the account, so I'd rather just switch. But everything else I want to have a plan for.

I have started by releasing my main email account (gmail) from Apple and in about 30 days I can set up my new account.

What is important for me is a lot of stuff that I think is associated with the iCloud account and not my email. For example contacts, notes, maybe documents not in the iCloud drive folder, messages etc.

I have a MacBook, so I'm hoping I will be able to utilize it to make the transfer as smooth as possible. I have already backed up the iCloud drive to the HDD. Is there a way to download a copy of the above mentioned and to transfer to my other devices later?

Every tip, trick and suggestion is very much appreciated!