Show posts in grid format

Hi there,

I have two questions:

1) When I go to a category/tag page, the featured images of the posts show up in a grid (https://build.shopmrmrs.com/category/styled-shoots/). However, on my home page, where the most recent posts show up, each post shows up in its individual rows, instead of a grid (https://build.shopmrmrs.com/). Is there a way to make the most recent posts show up in grid view as well?

2) How can I add padding around the photos in the grid so there is a little bit of white space between them?

Thank you so much for your help!