DSLR Cheat Sheet Required

[smokes]

Hi I have been forced by my wife to buy a DSLR. As I have to go to a big fat 3 day indian wedding in Mauritius and put up with the mother in law for 2 weeks.....

I am looking for a cheat sheet to set the focus aperture and iso and shutter speeds for a Nikon DSLR D5300 with a kit 18-55mm f/3.5-5.6G VR II lens

For Taking photos of the wedding and people with various skin tones from very light to very dark with brightly coloured dress in strong outdoor daylight and indoors in a temple /marquee

And also for taking pictures of people outdoors at night in in lit environment or a marquee.

Also I am looking for recommendations on using a lens filter to reduce the shininess of sweaty skin. it tend to be worse at night.

I am also looking at a 35mm f/1.8 prime lens to use in darker environments. would you recomend a cheap flash as well.

Regards Sammy