Even if you are a beginner, you can build an Ionic app in few steps. Please follow below steps.
Make sure you have NodeJS 6 or greater installed on your system. If not, then download and install it from here.
Once Node is installed on your system, install Node packages of Ionic CLI and Cordova by following command.
$ npm install -g ionic cordova
Here -g will install these packages globally.
Once you have installed both packages. Go to the folder where you want to create app through command line and hit below command.
$ ionic start MyIonicApp
Ionic framework uses this command to generate a folder and code related files. In our case, folder name will be "MyIonicApp".
After this, go to the directory which contains your application. In our case, it will be MyIonicApp.
$ cd MyIonicApp
Once you are in directory, run ionic serve command like below to launch your app in browser.
$ ionic serve
In the end, you will get your app running in browser. Your app will look like below picture.