In order to change your default style and layout type within a shortcode, you can use parameters with the google reviews plugin for wordpress.
Create reviews widget with style preset #8 and grid layout:
[google-reviews style="8" type="grid"]Create reviews widget with style preset #8 and slider layout:
[google-reviews style="8" type="slider"]Limit number of reviews to 10
[google-reviews style="8" type="slider" max_reviews="10"]Show header with place info and total reviews above reviews widget
[google-reviews style="8" type="slider" place_info="true"]Show reviews badge layout:
[google-reviews type="badge"]
