Hello

You can change the categories layout by editing that page with wp-bakery page builder:
https://screenshot.net/0ejdrs9

To change the categories title style go to Shop >> Categories styles as in the screenshot:
https://screenshot.net/0dql6fp

To add a border around the category picture. Please insert the below css in Theme Settings >> CUSTOM CSS >> Global Custom CSS

a.category-link{
border:2px solid blue;
}

Screenshot: https://screenshot.net/0owq7s1

Result: https://screenshot.net/098y1hq

Best Regards.