Switzerland is very unusual because it has four official languages: German (the most used, in 2/3 the country), French, Italian, and Romansch. Expect those languages spoken mostly near the borders of those countries and Switzerland, except Romansch, an isolated tongue used in Graubunden in eastern Switzerland
Trains run to the three biggest cities: Geneva, Berne, and Zurich many times a day from big cities in neighboring countries (Paris, Milan, Venice, Frankfurt, Munich and Vienna)
Highways go in through twisting mountain passes, from those countries as well.
Rail is probably the best way to get around. With the awesome scenery, you'll probably rather concentrate on it rather than driving, but driving will work fine too, but prepare for some steep roads and tight curves in some areas.