Google Apps Script how to select only google spreadsheets?

Question

Google Apps Script

It is necessary that the script takes all the Google tables that are on Google Drive (of which it takes: title, date of creation, author, link).
Now there are two problems:

1. How to select only google spreadsheets?
   
2. The creator of the document. It only outputs "DriveUser" at the moment.
   

How can I transform this code to get what I intended?

function fileInf() {
  currentSheet = SpreadsheetApp.getActiveSheet();
  var files = DriveApp.getFiles();
  i = 1;
  for (i = 1; i <= 1000; i++) {
    files.hasNext();
    var file = files.next();
    currentSheet.getRange("A" + i).setValue(file.getName());
    currentSheet.getRange("B" + i).setValue(file.getDateCreated());
    currentSheet.getRange("C" + i).setValue(file.getOwner());
    currentSheet.getRange("D" + i).setValue(file.getUrl());
  }
}

Answer 1

Perhaps the following selection for files will suit you better

var files = DriveApp.searchFiles('mimeType="application/vnd.google-apps.spreadsheet"');

Pro DriveUser. This is a system object, so you need to use one of its methods to get the information. For example,

...
file.getOwner().getEmail()
...