Can you help me for our project ,our project ideas is 'automatic speed control system using GPS sensor'?

Sanchita, you did not mention what help you want from our fellow engineers. It'd be nice if you could ask very specific questions on what help you want.

If this is for a vehicle speed control it might be far safer for a direct speed sensing and control.

How can I work on GPS ?using rasberry pi or using ardino uno?

@Sanchita 

You can start with any Arduino boards for now. Have a look at this tutorial :- https://www.instructables.com/id/Arduino-GPS-speedometer-with-a-ks0108-128x64-GLCD-/