Before you can start, you must first [Install] GASiC on your computer. Also check the [Dependencies].
The MANUAL file in the doc/ directory of GASiC is a good starting point. The command line interface of GASiC is explained there in detail. If you want to create more sophisticated analysis scripts involving GASiC, you should have a closer look at the example_script.py in the doc/ directory.
The [Virtual Machine] provides an interactive tutorial, please find the tutorial link on the VM desktop.