Where should we write the code after using ssdk create

I am having a doubt regarding what to do after ssdk create

ssdk create allows you to set up the AppNest application. You need to write code on the application created by the ssdk create command. Also, you can either work with serverless(your_first_serverless_app) or react app(your_first_react_app).

Please refer the project guide and the codelabs tutorials for more information.