Congrats on the tag and good luck on your upcoming hunt. I think when you get an Iowa anysex tag as a NR that you also get an antlerless tag with it, no? If so, maybe focus on tagging a doe first to get the jitters out of the way?? But one practical, physical thing to do to help with "buck fever" is to practice flexing your knees. Yep, flexing your knees.
You see, when on stand and a target approaches it is natural to get a little excited, almost everyone does this to some degree, although many work through it to where it isn't an issue. But, at first, most people will struggle with some form of this. One thing that most do when in this situation is to sort of "freeze up" and lock their knees, which reduces blood flow and begins to starve the muscles of oxygen and that can lead to shaking, etc.
If you concentrate on gently flexing and bending your knees though you can defeat this tendency and remain calm, or at least calmer, and better prepared physiologically for the shot.
As far as locating a buck...look at aerial maps of your intended hunting area now. In the timeframe that you are going to hunt the bucks will begin to move about during the day to find does...but a great percentage of the does will not be "ready" until say, the 6th through the 10th'ish. So identify "highways" that connect likely doe bedding areas, as the bucks, although losing their cool a little bit in anticipation of the active breeding phase, will still mostly use fencelines, ditches, ridges, etc, to conceal their daylight travels. For instance, a brushy fenceline that "connects" two blocks of timber can be exactly what you want in this time period.