First of all, its important that you have succeded with the installation of the V3.02 (it is likely you could stumble into problems if you are upgrading from V 2.xx to V3.02, see other topics in this forum)
The easiest way to getting started with Open AT v3.02 is by following the steps in the “Open AT 3.02 Tutorial” document and to use the “Project Wizard”. The Wavecom documentation strongly recommends using the “Project Wizard” when changing the project.
After the “Project Wizard” you can choose to develop and build your application either with a development environment (Microsoft Visual C++) or with the Cygwin command line. (both ways are described in the document mentioned above)
When porting to V3.02, you also need to be aware of that the some API functions has changed (see the “Open AT porting guide, 2.xx to 3.00” document).