When to sign and what to sign? New 2019 trailer purchase.

i agree with the signing after all is done, completed etc. right before you take it home. Please take some time, you mentioned you only saw it once. MAKE SURE YOU TAKE SOME TIME AND GO THROUGH THE MOTIONS AS IF YOU ARE LIVING IN IT, sit on the toilet, brushing your teeth,go to the fridge, get in and out of bed, watch tv etc, etc, etc. I missed some things on a unit a few years back and traded it in within a month of owning it. Good Luck & Be Safe !!!