You should note and acknowledge any trademarks of the Foundation and others.
You would not usually have to note any copyrights but you may need permission if using any copyrighted material yourself, and it is always good practice to acknowledge when such permission has been granted. That can also apply to any images you may use.
It is unlikely anything you write has to be approved by the Foundation or that they would insist on any editorial influence but it may be worth asking if they wish to cast an eye over it for correctness or comment out of courtesy upon completion.
That is likely to be more appropriate if publishing something substantial or using a physical medium such as a book where it is in the interests of both parties to have things as good as they can be.
Of course, one can probably get away without doing any of that, but it is always best to do it right, and credit is deserved just for asking. And one never knows; not Pi related, but I have had my fair share of 'cease and desist' notices for missing trademark attributions, incorrect use of logos, and the like. All innocently or inadvertently done and all amicably resolved, but best to avoid them to start with.