Congratulations on the new trailer; it's exciting to finally get what you ordered some time ago.
Here is a link to a PDI checklist on this site.
The dealership needs not only to show you how everything works, but to also give you time to do a thorough inspection of your new trailer. This is the Pre Delivery Inspection. Take your time; it may take a couple of hours to do it thoroughly. Be sure to take a flashlight for the dark corners.
The dealer needs to fix anything that needs attention, before you hand over money. That's what the PDI is for.
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch