To be quite honest, for non flight performance based issues, you need to go out of your way to get let go for HR or "the company doesn't like me issues." Like fabricating your entire flying background, lying about military experience, or just being totally an intolerable or a completely insufferable person.

Be a normal person, show up prepared with a good attitude and know one is gonna know who you are. And that's a good thing. There is no special meetings happening behind closed doors discussing what's going on with new hires unless problematic behavior is brought to their attention.