First or second lesson: English!
Use maps and realia. Where do people speak English? How far away are these places/how do you get there (plane, boat etc)? My home town/region. English words they know which are used in French etc.
Comparison of Christmas traditions here and in England: food, routine, cards, presents, decorations, celebrations.
Introduction to typically English sports, e.g. cricket, "The Boat Race". Discussion of "soccer" versus "American Football" etc.
Introduction to the music of The Beatles, where they come from, their popularity etc and the role they played in British Culture.
Typical food in the day of an English child, and "special treats": fish and chips, Roast dinner, afternoon tea. Get children to write questions to penfriends about this.
Talk about pounds, dollars, euros and francs. Show them some English money, get them to fill in each sheet matching pictures of coins with amount (using symbol). Talk about Queen on notes/coins.
Halloween, Pancake Day, Thanksgiving (in America), St Patrick's Day