Hello,

You can configure your images in Appearance – > Customize -> WooCommerce -> Product Image and find the size option for product page image as well as images in a grid:

Thumbnail width – Image width used for products in the catalog, Image width for the catalog is 350px;
Thumbnail cropping checkboxes:

1:1 – Images will be cropped into a square;
Custom – Images will be cropped to a custom aspect ratio, for example, 4:3 or there is the option to insert the aspect ratio
Uncropped – Images will display using the aspect ratio in which they were uploaded

There is no option to change the product gallery. Such modification would require complete customization which is not covered by our support.

Best Regards