1. Which variety of the German language should I study?

It depends on your purpose. However, it is highly suggested that you learn the standard German, as spoken in Germany. If you are aiming to use your German in another country, however, you may want to learn the standard German there.

2. What countries speak German?

There are numerous countries wherein German is considered the official language or co-official language. Apart from Germany, some of these are Austria, Switzerland, Belgium, Denmark, southern Italy, Liechtenstein, and Luxembourg.

3. Will I be able to communicate in German anywhere in the world if I learn standard German?

You may encounter some difficulties regarding vocabulary from place to place but you will probably be able to communicate.

4. Where can I learn German?

German language schools abound in many parts of the world. You can learn from a brick and mortar establishment or even through online courses. If you wish to be part of an immersion program, then going to a German speaking country would be your best bet.