I was named as the personal representative or trustee...

Even though you are named as personal representative in a will, it may not be necessary to open a probate. Gather a list of the assets you believe would be in the estate and meet with an attorney to decide if a probate is required. If you proceed with a probate, the Court must appoint you as personal representative (also known as executor in some jurisdictions). 

You will be issued Letters of Appointment and have certain prescribed duties and deadlines. Serving as trustee is somewhat different than serving as personal representative. Sometimes you may be asked to serve in both capacities. An experienced probate and trust attorney can guide you through the process of administering a trust and probating an estate in accordance with Arizona law.