Be careful of the side of the road on which you drive... other than that, we are, as George Bernard Shaw was credited with saying:
England and America are two countries separated by the same language...
You say biscuits I say cookies, for example. But you'll find that most all Americans will find that charming and express a desire to talk to you, especially to hear your accent (
I know, I know we're the ones with the accents). Be sure to pick up a guide (many available online) for currency conversions. You're coming at an opportune time since the exchange rate is very favorable to you. Your basic pound sterling is equal to $1.94 here in the U.S., almost two to one (see here:
http://coinmill.com/GBP_USD.html).
Leave the bumbershoot and bowler at home! Enjoy your visit...