I understand that each Mac has its predecessor in the HD already, ie. all former word processors etc are stored on here already (??)
Not so. There are no earlier versions of any software on an HD on a new machine.
Unless you specifically purchased iWorks (a suite which includes Pages, Numbers, and Keynote) when you purchased your new machine, the only text-handiling app included will be TextEdit.
You can purchase Pages and Numbers as individual downloads at the Mac App Store for about $20 each; or the iWork CD from the Apple Store for about $80.
...once I work out how to transfer Claris Works and Apple Works docs to the new Macbook....
Pages and Numbers can only open documents from AppleWorks 6.x. Documents in earlier AppleWorks version formats or in ClarisWorks formats can not be opened by Pages or Numbers.
If your old machine is still usable, it would be wise to convert all the older files to AppleWorks 6 formats before copying them to the new machine.