Your chances of getting hired in EMS right now are not something you should be too concerned about. There are plenty of opportunities. You'll get hired by how you conduct yourself in an interview and how you answer those typical questions such as "why did you decide to become an EMT" or "what made you want to work here vs somewhere else/ what are your long-term plans" etc. These interviews are pretty straightforward and are nothing to get worked up about. A lot of places just want to see that you're a professional, they can rely on you, and you're doing this because you want to.
As for studying-the text books usually give you key points to focus on for each chapter and have summaries at the end. Every chapter is important but definitely focus on patient assessment, human anatomy, medical terminology, and the cardiac/respiratory related chapters. Don't compare yourself to anyone when it comes to "time spent" studying- work at your own pace. What's important is that you understand the main points of each chapter. Don't worry about getting hired somewhere, that'll work itself out.
