The element type 'Future<Widget>' can't be assigned to the list type 'Widget'. code example

Example 1: The argument type 'Wrap' can't be assigned to the parameter type 'List

// Here you are wrapping a list as list
children: <Widget>[getList()],
// This should rather be
children: getList(),

Example 2: The argument type 'Future' can't be assigned to the parameter type 'void Function()'

REPLACE THIS:
onPressed: Navigator.push(...)

WITH THIS:
onPressed: () => Navigator.push(...)