By the time briefing has been completed and you have filed your reply brief, you should be acutely aware of the strengths and weaknesses of your case and know what needs to be covered during your initial argument to the court. At the outset, you should tell the court the nature of your case, the critical issues, what happened below, and the relief you are seeking. If there is more than one way that the court can resolve the case and grant you the relief that you are seeking, point that out. As to concessions, do not concede. Any important and necessary concession should have been apparent during briefing.
Any unanticipated concession made during oral argument is likely to appear in an opinion.
If you write out anything at all verbatim, it should be a short conclusion. You can then, when you run out of time, state your conclusion succinctly in a persuasive manner in closing your primary argument and your rebuttal. Your rebuttal is probably more important than your opening argument. At that point, you have seen how the court has questioned your opponent and how your opponent has responded to your arguments and the court's questions. You can point out to the court the points of agreement, the points of dispute, and the reasons why the court should rule in your favor.