You need to initialize a new Holochain app folder, with all the new files necessary to run a Holochain app, but you don't want to create them all manually. From the command line, enter the directory where you'd like to create a new folder. Instead of creating it yourself, just run
$ hcdev init your-app-name
This will create the folder, and within it you'll find all the starter files you need to start coding. Change directories into your new app folder (of the same name as your app). From here, two commands will help you.
The following will get you a web server for your new Holochain app running.
$ hcdev web
The following will run your tests, which is how we recommend doing application development: in a test-driven development way.
$ hcdev test
Start out by giving these three commands a try.
Commands to reference: