Austria is in the Schengen Area and the EU, so if you're coming from another Schengen country there are no border checks. Citizens of the US, Canada, UK, Australia, and most other Western countries can visit visa-free for up to 90 days. The currency is the euro. ATMs are everywhere, and card payment is widely accepted, though smaller cafes, market stalls, and mountain huts sometimes prefer cash. It's worth keeping some on you.
The language is German, but Austrian German has its own vocabulary and accent that can be quite different from what you learned in class or heard in Berlin. Viennese dialect is its own thing, and Tyrolean dialect is thicker still. In tourist areas, hotels, and restaurants, English is widely spoken. Learning a few basics goes over well — "Grüß Gott" (God greet you) is the standard greeting rather than "Guten Tag," and you'll hear it constantly.
Austria is one of the safest countries in Europe. Violent crime is rare, and you can walk around cities at night without much worry. Pickpocketing happens in crowded tourist spots in Vienna and Salzburg, as it does everywhere, but that's about the extent of it. Tap water is excellent throughout the country — in the Alps it comes straight from mountain springs.
Tipping is expected but not dramatic. Round up the bill or add five to ten percent at restaurants — you tell the server what you'd like to pay when you hand over the money rather than leaving it on the table. Shops close on Sundays, almost without exception. Saturday hours are shorter too, especially outside major cities. Plan your grocery shopping accordingly. Supermarkets like Billa, Spar, and Hofer (the Austrian name for Aldi) are your everyday options.
Austria historically had a strong smoking culture, and for years it was one of the last Western European countries where you could smoke in bars and restaurants. A full indoor smoking ban finally took effect in 2019. You'll still encounter more outdoor smoking than in some neighboring countries, but indoor spaces are now smoke-free.