First, you need to accept that you must learn how to prepare for prison. I do not want to give you false hopes or expectations: prison is not easy. You will feel alone, isolated, and likely very unhappy at times. I know that you are going to be facing a real challenge.
With that in mind, I recommend you hire a prison consultant. Someone who can tell you more about the process, what you will be facing, and what to expect. I used to think that this would be a bit overkill, but I recently experienced a friend going to prison, and they told me that the prison consultation they got was a big factor in seeing out their sentence.
If nothing else, you will understand what awaits you once imprisoned—best of luck.