To demonstrate EVEN and ONLY testing, you would need to create a batch process that will abend. There are many easy ways to do this. Force an 0c7 (invalid numeric), or 0cb (divide by zero), or an 013-20 (different blksize between the process and the file).
Then you can run jcl that will run or not run depending on if the job abended or not.
You need to read about EVEN and ONLY in the manual so you will have a clear understanding of how these work. If you find something in the manual that is not clear, post what you found and your doubt. Someone will be able to clarify.
Hope this helps,