Please stand outside with a clear view of the sky. The very first GPS fix can take minutes since the device has to know where it is in order to know which satellites to check for.

The speed indicator on top of the map shows the raw reading of the GPS.
For analysis the speed and heading is the average of the last 10 gps points. When you are sailing for 10 seconds in a straight line with a constant speed, the values are used for statistics