I am not aware of any tutorials on how to implement a CPU in TPT in a general sense. Most computers people make are quite specialized and utilize different tech/features. I suggest you read up and get a good idea of how a basic CPU functions, then consider what elements you know how to work with and how you can apply them to make something that does what you want.

Here's a nice video that gives an overview of a general purpose cpu and its parts:
And of course don't forget the visual 6502, a simulation of an actual CPU that went into production.

Here is how all the parts are connected (generally).

Anyway I wont spam too much here, wikipedia is your best friend! If you need help with the elements and techniques send me a pm :)