how do i copy imessages and sms onto icloud?

You can't copy messages to iCloud. Your iMessages are completely separate from iCloud and you don't need an iCloud account to use iMessage. Your sms messages are sent from your cellular provider and also have no connection to iCloud.

If you are trying to receive your iMessages on your other devices, just sign into iMessage with the same Apple ID (in Settings>Messages>Send & Receive).