We did Candlelight processional two years ago and this is how it worked then.
There will be two lines formed for entry into the seating for the show. As you are facing the stage, the line to the LEFT (going towards France) is for those who booked the package. The line, as you are facing the stage, to the RIGHT (going towards Germany) is for standby seating only.
All of the people that have the package will be allowed entry first to sit where they want. Immediately after the last person clears that entry (even before they are seated) they will open the other line and those people will dash in trying to get good seats.
There will be a lot of people with the package. That line will be long too. We got in line about an hour before the show started and we were still pretty far back. The seats we ended up with were decent but not all that spectacular. Buying the package guarantees you a seat but not necessarily a good seat. Still, many of the people who wait in the standby line will not get a seat at all so it is worth it to book the package, especially if you were planning on having dinner anyway.
I would recommend that you check out the theater area earlier in your trip and have a general idea of where you would like to sit so that once you get inside, you can go to that area immediately. If you hesitate, you are going to find yourself in the back!!!