First wash or 20th wash, I use a whole lot of the cheapest automotive wash soap (sold by the gallon) and a mop-material covered sponge marketed for washing automobiles in a 5 gallon bucket of warm water, and rinse with an open hose to avoid spraying because spraying leaves a lot more water spots. Allow the rinse water to flow over the surfaces. One thing certain, you will miss some dirty areas requiring touch-up.
About waxing the first time, I would wait 6 months or the fall, whichever comes first. In the mean time, do your best to avoid parking under sappy trees. Clean off sap & bugs frequently until that first waxing.