To get CpmFetch working, you really only need to know how edit files to insert some PHP calls. This can be accomplished with a little attention to detail and following the instructions carefully. In some cases it can be a bit harder than that - in that case see the FAQ in this document, then post online as noted in the support section.
If you have some knowledge of PHP, you can do some pretty cool stuff. I recommend learning PHP a little bit, as it will help your web site immensly.
For many many moons I have pondered what level of user I should write for. I try to write for someone who has a small knowledge of PHP. Getting the basics going is an exception - anyone should be able to do that. For more advanced and potentially cool stuff I expect some knowledge of PHP. I have little enough time and do not want to spend it answering basic PHP questions.