Creating a view
Go to Structure > Views > Add View and follow the instructions to select what kind of content you want to display. Select Create a block and choose Bootstrap Grid and fields for the display format.
Styling a view
The College Drupal Distribution has custom views plugin called Bootstrap Grid, which allows view content to be styled into a grid of rows and columns. It has several options for styles including white, gray boxes, cards, card groups, and a masonry type layout.
When using the card option, you can add additional bootstrap classes to view fields such as card-title, card-body, card-footer to take advantage of various bootstrap card features. Find more info on bootstrap cards at https://getbootstrap.com/docs/4.3/components/card/
More information: https://drupalize.me/series/user-guide/views-chapter