What should be the structure of the data storage system for an online store on React Native?

Question

Online shopping

Hello.
I am making an online store (learning to use React Native). It is necessary to store the hierarchical structure of the catalog, products, personal data of the user (orders, profile, etc.). Those. there are three big entities. The personal account will be on firebase (a simple key / value structure is suitable for this) using the realtime component. Everything is clear here. Each user has access only to his own part of the firebase database, configured by the rules.
Further. How to be with the catalog and goods. Goods - clearer, catalog - not entirely clear.
If goods can still be stored in firebase so that everyone has read access, but only administrators have access to editing, then there is a problem with the catalog. It would seem that writing a multidimensional array is easier than a steamed turnip. But here are the links... The id of the category is changing - how to track changes? How to relink a bunch of products to a new category? No pivot table, no relationality...