You are welcome to the community.
First,you can setup apache Juneau. And also you can go through the documentation to get an idea about the components. Let us know if there are any blockers.
And then you can find the Juneau Petstore repository here .Try to set up that one as well. This will be the repository selected participant will be working on throughout the project. Also, you can find Juneau Jira here try to find a task and start working on it.
And don’t forget to subscribe to the mailing list of Apache Juneau as well.