Around 13 million people - mostly in Greece and Cyprus (where it is one of two official languages) - speak the modern form of Greek. However, Greek speakers are by far, more international than South-eastern Europe and can be encountered in the USA, United Kingdom, Canada and Australia where they all form a significant (and growing) diaspora. Moreover, because of the importance of Greek civilization to the West, many things the Greeks invented or were the first to do are enmeshed into our own culture: from drama and political theory, through classical architecture and even the Olympic games.
The language's origins date back nearly three and a half millennia but this course from Languages at Leicester is specifically in its modern form. Useful if you plan a holiday to Mykonos or the Peloponnese but not aimed at those wishing to read Homer's Iliad or Odyssey (although it may give you a leg up in that direction).