As long as you don't have a criminal records and you do everything correctly you'll have no problems getting an air side pass. My first was at an airport while I was still learning at college, I needed references for the past 5 years from school + college plus a personal reference for the gap between leaving school and starting college.
My employer basically left me to get all my own references and I wasn't sure exactly what was required which was why it took me months to get mine, but if your employer do all the phone calls you'll have no problems.
Good luck