Also, make sure you’ve set the team number in the limelight interface to match the team number on your robot. What you are probably seeing is the default value that network tables returns when it didn’t actually find the table.
getValue() returns a NetworkTableValue, which is basically a typed union, as NetworkTable values can be one of several possible types. The methods on NetworkTableValue can be used to figure out what type the value is, get the underlying data, etc.
However, there are more specific methods for individual data types on NetworkTableEntry to make things easier. If you know the type is e.g. a double, it’s much easier to use NetworkTableEntry.getDouble(), which simply returns a double.