Welcome to your first lab. There are no changes needed in order to run the lab - it will serve as a guide to both Java code and navigating the IDE (your code editor) and test cases.
If you look within the src/main/java folder, you will find two informative Java classes, Guide.java and GuideMain.java. These files have some code with some informational comments about the general structure of Java. No changes need to be made to these files. It is OK to not understand all the information, as the concepts will all be involved in future labs.
If you look within the src/test/java folder, you will find the Java class GuideTest, which is a test file. Even if you have prior experience with Java, the concept of testing and TDD (test-driven-development) is likely unfamiliar to you. Test cases will be instrumental in completing labs. Test cases are essentially scenarios built that ensure that code in a class such as Guide.java functions as one would expect in a particular scenario. You should never modify the test cases in the labs, as this is likely to break the lab entirely. Every lab has been thoroughly tested to not require any modifications to the tests.
You will also find that there is a file named pom.xml. This is a build file which allows the project to contain open-source tools, such as the tools used to write test cases, into the project. The program used to do this is called Maven. You should never modify this file.
All future labs will involve modifying code in src/main/java such that all the test cases in src/test/java. No modifications need to be made here as the code has been written to pass all test cases from the start. You should, however, still run the test cases in GuideTest to familiarize yourself with the process of testing your code. You can run tests generally by clicking the 'run' button (usually drawn like a triangular 'play' button) inside a file containing test cases.