Are you getting:
Unable to connect: retrying (1)...
Unable to connect: retrying (2)...
Unable to connect: retrying (3)...
Unable to connect: retrying (4)...
Unable to connect: is the sketch using the bridge?
If it is the first then close the Serial Monitor window, select the USB connection in the Tools->Port menu and reopen the Serial Monitor. The instructions at the top of the example sketch tell you to use the USB.
If this works here are the lessons to learn:
Follow the instructions EXACTLY
If you have trouble make sure you followed the instructions EXACTLY
Report error messages EXACTLY as you receive them, AFTER searching this forum for them, this is a very common error and there are many posts here about it.
Youtube is great and there are lots of examples there, if you have trouble with one, ask whoever posted it on Youtube about the problem.