I am seeking coding for my project. I would like to build a nano satellite model which able to sense change of temperature and pressure, has GPS function, able to capture image
If you just want someone to write a program for you please ask in the Gigs and Collaborations section of the Forum and be prepared to pay.
If you want to learn to program yourself the examples that come with the Arduino IDE are a good place to start. They probably cover all the techniques you will need. There are also many online tutorials. Also see the Useful Links Thread.
And if you are going to learn how to create your program I suggest you break your project into several smaller learning parts. For example write a short program to learn how to use the transceiver and another to learn how to use the camera etc. That is how all complex programs are developed and by dealing with each part separately it will be much easier to find relevant examples and advice.
There are GPSs you can get for satellites, you do need something of a license for them as I recall, and they aint cheap.
Getting images back from a small satellite at very long distances is not so very simple, so you would need to think how it might be done in reality so the model is realistic.