Did you open your bundle and look at the Symbolic name in the MF file? Did you follow these instructions to create the System user? To successfully query JCR data, create an Experience Manager System user by performing these tasks. 1. Open http://localhost:4502/crx/explorer/index.jsp.2. Login as adm...

To show an example of what Joerg stated - see this that shows this via an API - Adobe Experience Manager Help | Replicating Adobe Experience Manager Content using the Replication API

Install the package on a second AEM DEV instance and see if you get that result. It could be something in your AEM environment.

Is the outer component that AEM Responsive Grid? There should be no issue when you have components within the Responsive grid. Or are you building a custom component that contains child components.

Lokesh - a top AEM Community member - addresses correct way to handle this use case here: Best practice to query JCR data using QueryBuilder API

Follow this end to end tutorial - the grid worked perfectly when I followed this one: Adobe Summit 2019 | L767 - Getting Started with Adobe Experience Manager Sites Development

I cannot find a good example on how to build a solution using AEM and magento.

The JavaDocs state its a valid API - FormData ("The Adobe AEM Quickstart and Web Application.")

As Jierg suggests, use a public facing API that AEM exposes.

Do you mean you want to code a Search component for your site?