*Sorry for late replay*
I am from sweden and used english during the whole con EF 18 and it worked perfectly well, both in the con hotol and sourounding Magdeburg are as well as travelling to and from, Magdeburg.
As for me I would recomend a stopover and Jet lag fight in Berlin, its a two hour train ride (every hour or so during daytime) from Berlin HBF to Magdeburg HBF and the city is bristling with shopping and historic sightings such as World/cold war era relics and museums. If you have any interests in shopping and historical sights Berlins is a great place to get a feel for europe, and youll be fine with English, for most parts at leasts. Setback is that it isnt THAT many intercontinental flights that I know about from Berlin to USA, Lufthansa for example uses Frankfurt and, uh, is it Hannover? as its main hub.
Another city well worth a visit is London, Ive been there severel times and its a great shoping and theathre city, well up to New Yorks standards. From there you can take a short flight to good rail connection cities such as Amsterdam and Hannover, or might even take the eurotunnel to Paris and connect to europes fast train systems from there.
Magdeburg and EF was great fun, and well worth a visit, even thou it might be an idea to start with visiting any of youre US cons if youre totaly newbie to the whole con system, just to get a feel of how a big con works.