Putting Container with Text above List View in Flutter

I want to place a simple Container with some text above a ListView in Flutter. I tried to place the text in the AppBar but I found out the AppBar is not intended to do so.

It should look something like this (except the description should be outsourced to a dedicated container). Example Image

I tried following these instructions but wasn't able to accomplish anything.

return Scaffold(
  body: Container(
      padding: const EdgeInsets.fromLTRB(0, 20, 0, 0),
      child: ListView(
        scrollDirection: Axis.vertical,
        children: [
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
          Category(),
      ],
    ),
  ),
);

I am new to Flutter and new to stackoverflow so I hope this question is fine. Thanks in advance and kind regards :)

Firstly, wrap your ListView with Expanded then wrap it with Column. Here is some code examples:

return Container(
      padding: const EdgeInsets.fromLTRB(0, 20, 0, 0),
      child: Column(
        mainAxisSize: MainAxisSize.max,
        children: [
          const Text("HEADER"),
          Expanded(
            child: ListView.builder(
                itemCount: 10,
                itemBuilder: (context, index) {
                  return Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Container(
                      height: 30,
                      width: 50,
                      color: Colors.red,
                    ),
                  );
                }),
          ),
        ],
      ),
    );