Hi Skyjumper,
You won’t need a mattress pad unless you want to change the feel of the mattress but a mattress protector is important to protect the mattress from moisture, body fluids, and skin cells (that can encourage dust mites) and accidents that can stain the mattress and void the warranty. It can also help keep the sleeping surface in a more hygienic condition because you can easily remove the protector and wash it as necessary. There is more about the pros and cons of different types of protectors in post #89 here.
You won’t need to choose a fitted sheet that is exactly the same size as your mattress and most sheets will indicate a range of mattress thicknesses that they will fit. As long as your mattress is “in the range” and the pocket is about 2" or more than the thickness of your mattress and they aren’t “extra deep” and designed for much thicker mattresses you will likely be fine. There is more about sheets in post #7 here and the other posts it links to.
Thanks for the kind words and your feedback and I’m glad the site could help you!
Most important of all … congratulations on your new mattress … and you’re certainly making a great quality/value choice 
Phoenix