Where can I edit the size of the images on my shop page?
And where can I change the style of the product page, because I want to have one normal size picture and the additional product photo’s on the left side in smaller size.
Hi there
Hope you are having a good day and thank you for your question
the image size of the products can be configured from appearance > customize and check Woocommerce settings
The product page has a predesigned layout, I’m not sure if you can make such changes you explained in the question 
Thanks!
Colorlib Support Team