Hey Gebreabzgi Pawlos,
You can't develop your application without GSM module.You want to first test in proteous but GSM module not present in proteus.But if you want another part of your application rest of GSM,you can do it. Almost GSM module is communicate with controller through UART port.So learn the configuration and make code for serial communication. You can test in proteus using virtual terminal connect with controller's serial port.