The pins you are trying to use are not designed for that purpose, these pins are used to program the Internal Flash Memory of the board with a debugger like a DediProg or another.
I suggest you to first check the requirements of the servo you are using, if you try to power the servo with the board but the servo requires more power it could damage the board. Take a look at the Board Shield Testing Report, you will find some configurations with servos that may help you.
About the code to make it work, check the examples on the Arduino IDE for Servos File>Examples>Servo these examples are for Arduino. Currently, there are no examples for C++ but you can use the MRAA and UPM libraries to control the different GPIOs on the board.
I hope this gives you an idea on how to continue on your project.