I'm not sure there is anyone out there who enjoys marking... correct me if I'm wrong. A lot of the nervousness is around making the wrong decision in the moment which is totally understandable for players at all levels. The World Squash Officiating website has a really good interactive tool for squash players of all abilities. The course runs you through the basics of refereeing and allows you to watch videos and read material before taking a series of tests. Pass these tests and you're on the way to getting a referee qualification.
To do the course and test is free, but to make it an official qualification and to move up the ranks there is a £19 charge at the end.
