Regional experience and expertise when it comes to cultural, social, political issues as well as language expertise are certainly big pluses. Any language that falls under "Critical" languages is especially sought after. If you speak multiple languages, even better. https://www.nsep.gov/content/critical-languages

Depending on what aspect you want to go into (analytical, clandestine, cyber etc) you would need certain educational qualifications. For analysis, something in the liberal arts or social sciences like history, political science, geography etc. For clandestine stuff, a military or law enforcement expertise or background could be helpful as well as some liberal arts stuff mixed in. With cyber, more technical stuff is obviously helpful: Networking, telecommunications, coding languages, security, malware etc. Technical knowledge will also be helpful in all of those areas given the increasingly critical role that technology plays in the intelligence field. As to entry level jobs, they offer summer internships for students in college and internships for recent graduates. They also have more entry level jobs that have a training process. Most of that information can be found online at the various agencies. Above all, just be passionate about what you are interested in and do not accumulate a criminal record.