I am the caregiver for my 98 year old father but another sibling is the power of attorney. Am I entitled to see his will and trust?

A Will is a private document and has no legal effect until a court admits it to probate.  Your father does not need to let anyone see it. A trust is a private document and remains so absent litigation.  However, in some states beneficiaries over a certain age are entitled to an annual accounting. It is not clear from your question whether your father has a revocable living trust with a "pour over" wiil.  If so, while he is alive he is the only beneficiary (unless he and your mother made the revocable living trust and she is also alive, in which event she would be the second beneficiary).