Graubünden (Romansch: Grischun, Italian: Grigioni) is a mountainous canton, from maps one can see that it is dominated by the Engadine and Rhein valleys. However these have many a side valley that offers hidden and isolated splendours. From Graubünden, rivers flow to the Mediterranean, North and Black seas; it is the watershed of Europe. It is a spectacular landscape, home to Switzerland's only National Park. Graubünden combines wild rugged scenery with charming villages and a unique Romansch culture. The capital is the ancient Chur which has existed since roman times (Latin: Curia) it is a small city with a fully cobbled and painted shuttered old quarter. Like the rest of the canton it is modest; concealed here is some of the best outdoor sports in the world, ancient mountain towns, stunning panoramas, three official languages and distinct culture, yet it does not boast; little is known by outsiders of the delights within.
In most of the canton, German is the official language, but the main language in these areas is Alemannic, or Swiss German as it's called. The northern part of the canton (including Chur) speaks High Alemannic dialects and the southern parts Highest Alemannic dialects. In some parts the official languages are Italian or Romansh, with many parts bilingual in German and Romansh.
You should be able to manage with English, especially, but most certainly not only, in the German-speaking part, but the most convenient lingua franca is German; since both "German"-, and Romansh-speakers are usually taught German in schools, it is a language you can speak with the vast majority of the people in the German-Romansh bilingual parts. Even in the unilingually Italian/Romansh-speaking parts, people will often speak the language since even there they are taught it in school.
There are no airports in Graubünden so the easiest option is to take the train from either Zurich or Milan, where there are international airports. You can also take the train into Zurich Bahnhof from other European cities, as it is an international train station.
The Rhätische Bahn (RhB) is the the train system in Graubünden. The trains are always on time and can get you to most places. Post Buses will take you from the stations up the moutains to the villages.
Traditional Romansch foods include Capuns,Rosti and Pizokel. Rosti is shredded potatoes, fried, and cheese melted on top. Occasionally bacon and a fried egg is added on top of the rosti.
There is very little crime in Switzerland, Graubünden being one of the safest cantons. There may be areas of Chur that could be dodgy after dark.
Italy and Austria border much of Graubünden and both countries are easily accessed from the Engadin and San Bernadino pass. There is also the rest of Switzerland to explore, including the nearby Italian-speaking region of Ticino