When you get word of something, you find out about it. You might only get word that your school is canceled because of snow after standing at the bus stop shivering for an hour.
It's most often an accident when you get word of something — you learn about it, rather than being told about it directly. You could also say that you "get wind" of something, or "catch wind" of it. If you get word that your neighbor's having a pool party, you can either put on your suit and walk next door, or sit at home feeling annoyed that you weren't invited.