Help! New GRD IV coming tomorrow!!

I am a longtime Pentax slr and Q shooter but the GR has been haunting me for a couple of years.  So, as the title says, I need some quick help for a country boy going street shooting!!!  My wife and I will celebrate our 40th on a cruise leaving this friday and I decided to try an entirely new adventure in photography.  As a retired biologist I usually shoot "bugs", birds and flowers so I am a pure neophyte at this. So, any advice will be appreciated and this ol' brain will "pull an all nighter" to give it my best.  Thank you all and especially Tom, whom I have privately written for 6 months or so.  Patrick