Right on man! Just know the flows and do your best, the first few legs you will feel overwhelmed, but don't worry that is normal. The LCA will know this is your first rodeo in the 121 environment, so he/she will help you out and make sure you don't mess anything up too bad. I had my IOE out of ORD, so I just went through all of the jeps for SID's STAR's, Approaches and Taxi Diagram to make sure I would have some sort of situational awareness in the terminal environment. To be honest, I was still like...wait, what?? for the first few legs in and out of there lol. By the 3rd or 4th day it will all feel much more normal, and you will be amazed by the pace you are able to keep during the day with quick turns.