regarding grids with form

What is the "supervisor form"?

In general, you can get details of files AFTER the form has been submitted.

Assuming that document is already uploaded, as Stefan notes, you can retrieve those properties using the document() function, such as:

a!localVariables(
  local!doc: /* Your Document(s) here */,

  a!gridLayout(
    headerCells: {
      a!gridLayoutHeaderCell(label: "Document Name"),
      a!gridLayoutHeaderCell(label: "Uploaded By"),
      a!gridLayoutHeaderCell(label: "Uploaded On")
    },
    rows: a!forEach(
      items: local!doc,
      expression: a!gridRowLayout(
        id: fv!index,
        contents: {
          a!richTextDisplayField(
            value: a!richTextItem(
              text: document(fv!item,"name")
            )
          ),
          a!richTextDisplayField(
            value: a!richTextItem(
              text: document(fv!item,"lastUserToModify")
            )
          ),
          a!richTextDisplayField(
            value: a!richTextItem(
              text: document(fv!item,"dateCreated")
            )
          )
        }
      )
    )
  )
)