You wont have any problems if you are honest, direct and friendly. Think before you speak, but only if you are abnormally prone to putting your foot in it. As with any prejudice, anti-Americanism falls away in the face of a pleasant representative of that group, and I think the stereotype of the obese, check-trousered, rough-shod riding Yank abroad has pretty much died out, even here.. . Enjoy your stay, and I hope you'll meet loads of new friends.