Thanks for reaching out, @Opals_Shop !
It sounds like your question may be related to collections, for which you can set up either an Automated or Manual Collection as per our help doc. I encourage you to review that to familiarize yourself with both collection types as well as how they each work.
If you are currently using an automated collection you will have to switch to a manual in order to prevent items from being added on their own.
Note:
Automatic collections cannot be converted to manual ones or vice versa - instead you will have to create a new collection that meets your criteria needs.
I trust that helps,