Luna here from Shopify. Thank you for posting your concern in our Community forums. I’m more than happy to look into this with you.
To gather a little bit more context, are you referring to your collections? Collections are the categories that you can create in order to group your products. For example: Women’s clothing, Men’s clothing, Children’s clothing, etc. Once you create your collection, you will need to add it to your navigation settings for it to appear on your storefront.
If your collection has already been created but is not displaying on your store, I suggest ensuring that you have added it to your navigation. To do so, you can follow these steps here:
We also have a great video guide that you can check out here. In regards to your images, you can edit the collection display image, or change the order that the products are displayed by following the steps listed in this Shopify Help Document.
Let me know if this helps or if you have any questions!