To confirm that you purchase a Classic Launch Pack, simply log into your NC Account and click on the Transaction History tab. Then click on the Lineage II tab. Your Journey or Chronicle (whichever Pack you purchased) Launch Pack will be listed there along with the date and purchase price.
When Lineage II Classic launches on October 3, 2018, a Classic Launch Pack serial code will be applied to your NC Account. Instructions on how to activate the code will be provided closer to launch.