For calculating (estimating) tire pressures I like the Beto Tire Pressure app that is based on work by Frank Berto and the basis for much of Jan Heine's initial work. It's available for both Apple and Android.

The OP doesn't state what type of bicycle he will be using, so I'm assuming a standard road bike with down-turned handlebars. Following that, entering the various weights given, the app returns 71 psi rear, 38 psi front. Many above have suggested that such a low front pressure would be absurd. Whatever. Just begin by treating these starting points and experiment from there.

I follow these recommendations for my own bike running 54-ish rear and 42-ish front (I typically just round to the nearest 5 psi and have no estimate for the accuracy of my gauge). Note that my weights and weight distributions differ (significantly) from the OP's. I may even DROP my pressures from there, as an experiment.

One reported advantage to riding lower pressures, that wasn't mentioned above, is a reduced likelihood of flats.
Cheers!
And have a great trip. (And don't obsess too much about this -- at least go high enough to avoid pinch flats.)