So please help me with that
What, EXACTLY, is "that"?
I m planning to calculate the GPS bearing between two points of a quadcopter.
If you are using TinyGPS++, the library has a method to calculate the bearing between any two points.
If you aren't, you should be.
I want to calculate the angle between the base station and the quadcopter position
That's not quite the same thing as calculating between two points on the quadcopter path. How will you know where the base station is?
with that I need to control the 2 servo motors in the base station
How will you get the bearing information to the base station? Why not just tell it where the quadcopter is, and let the base station figure out the bearing to the quadcopter?
because I'm very new to arduino.
That is no excuse for piss-poor requirements.