Van is located in the garage between Outside and Lockers, next to the loch n load. Once the power is on, press the button to lower it.

Gas cans locations:
In the upstairs room of the war room
Backside office right next to Saxton Ale
A 3rd somewhere near power room, but don't quote me on that.
In Server room corner.
Near Gas Trap tanks, underneath them.

Once power is on, go to the War Room to PAP (use locked down terminal, interact with wall, then teleport)
The locked down terminal near the first can is where you get the Documents. Teleport with the documents to complete your work.
Run to the van, then fuel it and interact.
There is a locked down terminal in the same room as the first Gas can.

I don't know anything else