I'm not really sure when is best to show up to get the tailgating etc all in ... but I think the doors open one hour prior to kickoff. (And for some reason, kickoff always seems to be 8 minutes after the given time ... )
You should be able to pick up your tickets at any time. Head for the SE corner of the stadium, that's where the will call booths are. Tailgate parties are in the east parking lot, too. So you don't need to worry about taking too much time to get from a tailgate party to your seats. Unfortunately I can't give nearly enough advice on tailgate parties
But you're not all that close to me ... section F, row 45 ... same side of the stadium, but that's about it!
(Oh yeah, once inside McMahon, you can only go from one side to the other by going around the north endzone, so you may want to instead go around the outside (to the south) and enter through the SW corner, since you're sitting in C)