If you have Elite Plus status skip the VIP lounge and head to the China Eastern lounge it's by gate 21. The VIP lounge is worthless IMO. It's basically four walls, no ceiling and small area between gates. Maybe two plugs in the whole area.
Checkin opens at 1230 but only for self checkin and bag drop. Agents don't show till 130pm. I was on delayed PVG-DTW yesterday and can say terminal one is junk. Normally DL use jetbridges, but sometimes use the bus gates.