Hi Kathryn, There are a wide variety of IT jobs, and each requires a different set of skills, education, and core competencies that likely depend on the organization and its customers. I don't necessarily think CompTIA is the only IT certification of value and there are lots of options for expanding your IT knowledge. If you already have a degree (in something), that's a great advantage in the job market. If not, you can find lots of useful software and IT training from sites like Lynda.com, Khan Academy, and also edX, which is a new program that colleges and universities are participating in that offer free online training: https://www.edx.org/course/subject/computer-science.
I think a hiring manager would care as much about your education/training as they would your real world experience working in IT. You might consider taking some online courses in computer science or technical support training, and then try to get a few contract jobs (like on dice.com) to gain some field experience. Good luck and let me know if I can help further!