The PNR is in the flight summary screen; note that this is different from the record locator CTO references which is listed on the top of the summary screen.

I always request advance ticketing. Too many times I have shown up to the airport only to find my reservation was never ticketed.

What will be interesting going forward is how they will process upgrades on codeshare flights. Currently if you buy a ticket with US code operated by UA they will allegedly only process it day of departure. I know on CO with codeshare flights that isn't the case, have always been upgraded at the EUA window.