CHICAGO — It’s 1:27 p.m. on a perfect summer Saturday in Chicago, and you’re down by Lake Michigan entertaining the masses. More than 43,000 people are inside Soldier Field getting their first opportunity to see how you’re handling your new job. They’re hanging on your every move. In this moment, in the preseason opener against the Miami Dolphins, you have urgent responsibilities, namely leading a successful two-minute drill after a quintet of dreadful possessions by your offense. You are Justin Fields, the 22-year-old rookie quarterback of the Chicago Bears, pronounced by many in your new cit…