Problem with shots on a very sunny day

[mocha2204]

Hi All,

I am new to photography now and starting to take more pictures on a tour mostly on a very sunny day.

I am having problems with the outcome like shadows, over exposed background and dark faces, examples below.
My gear is D90 with nikon 35mm f1.8 lens

I usually shoot in A (aperture) mode and use f5 for people shots and currently not having any filter.
Do you think by attaching a UV filter will help with decreasing the shadow, over exposed background and lighter face for people shots?
Sometimes I got quite frustrated that I turned to Auto mode

Thank you so much in advance. I will be having another trip to hamilton island in mid Jan and I am guessing the weather will be very very sunny.