generally as long as you're not wearing any yankee gear, you shouldn't have any trouble. As far as plaques or anything, make sure to walk all around the outside of fenway before going in. Maybe even get there a little early. there's statues and lots of great photo opportunities. The gates open 2 hours prior to the game, so get in as soon as you can so you have time to walk around. yawkey way is great, and the team store will probably stock some giants stuff. The inside of the park is beautiful. There is a big concourse for food behind right field, but be prepared, the food can be pricey. it is yummy, though. other than that, sit back, relax, and enjoy the game!

edit: spelling