the service manual for my 65 malibu says to lube the door hinge pins with "lubriplate". What is the equivalent? I have white lithium spray grease, lots of other greases, and good old motor oil. What should I use for the first lube after installing new door hinge pins and bushings?

lubriplate is a brand of lubricant, it is like a white grease. I don't see anything wrong with using white lithium grease for what you are doing,thats what I use on my door hardware.

I also have a white grease in a small plastic tub. Maybe that would be better.

yes use the stuff in the tub it will be better then the spray, of course you could spray the pins and also brush more on also