How to use/revise source codes?

[ShanGao]

I am a newbie here.  I can use existing templates to make apps,  but how to use/revise available source codes to make my own apps based on existing templates.  For instance, I download a source code. It is a zipped file including the following files.  Where to start?  How to quickly deploy the application without a developer.Only a developer can do the job?  I want to learn some simple and quick skills to make simple apps based on existing templates.  Your advise or guidance is greatly appreciated.  Shan

[RickeyFight]

This is from an esri Github page https://github.com/Esri/geoform-template-js

This basically applies to all webapps they have templates for

Deploying

1. To deploy this application, download the template from Portal/ArcGIS Online and unzip it.
2. Copy the unzipped folder containing the web app template files, such as index.html, to your web server. You can rename the folder to change the URL through which users will access the application. By default the URL to the app will be http://<Your Web Server>/<app folder name>/index.html
3. Change the config files to your layers.