Another piece of advice. Start STUDYING!!!
The GCOR is one of several rule books you will be referring to. It reads like war and peace.
Memorize the Signal aspects and indications. These must become as automatic and comfortable as scratching an itch without thinking about it. The problem with memorizing signal aspects is that different railroads use different signals for the same indication. One way for us will be different for you, but mean the same thing. It can be confusing. So I recommend getting the terminology down at least,then when you start training find out which signals are applicable to your railroad.
I can't speak for CSX but the definitions in the back of the GCOR would also be highly advisable to memorize.
I just marked up from my conductor training and it was one of the more academically difficult things I've done in recent memory.
Good luck. 2 days on the job and I'm having a blast doing it. The people I work with are a lot of fun.
LJ Pierce
Peace, Through Superior Firepower