Is it too hard to process for a green card?

I am sorry friends for I cant be online tomorrow again, me and my husband will go to Charlotte North Carolina. On Thursday will be the schedule of my biometric for my green card.
I am just hoping that I have all the requirements for that biometric schedule, because last time we file for a green card they returned all the papers that we sent to them, because they said our requirements was not complete. is it too hard to process a papers here?
Thanks for visiting my site always.