Answers for "flutter top margin on column"

flutter vertical space between containers

Column(
  children: <Widget>[
    Widget1(),
    SizedBox(height: 10),
    Widget2(),
  ],
),

column each child padding

Wrap(
  spacing: 20, // to apply margin in the main axis of the wrap
  runSpacing: 20, // to apply margin in the cross axis of the wrap
  children: <Widget>[
     Text('child 1'),
     Text('child 2')
  ]
)