Our demo application is in https://github.com/spring-projects/spring-petclinic
It’s a Java based application built on Spring boot framework. It has an in-memory database populating all the startup data. All you need to do is to clone the source code from Github to your local and run some maven commands.
Except for Maven, you don’t need to install anything.
For newbies, it’s going to be very handy to work on that web application. It does not have a very complex HTML and CSS structure. Besides that you can play with the application code, make some changes (adding custom automation id’s to web element or even adding a new functionality) and redeploy the app.
All the commands to run the application are written on GitHub.
By the way you can also use this application for Performance Testing too after deploying to a cloud provider or in your local. It will be very fun to work on it.
Hope you’ll enjoy the app and have a good automation journey!