By default, Generate Blocks has empty paddings for new containers. This means, for every container, you have to set paddings for three sizes manually. This snippet adds some default paddings to start from.

gb-default-paddings.php

add_filter( 'generateblocks_defaults', function( $defaults ) {
    $defaults['container']['paddingTop'] = '30';
    $defaults['container']['paddingRight'] = '30';
    $defaults['container']['paddingBottom'] = '30';
    $defaults['container']['paddingLeft'] = '30';
    $defaults['container']['paddingTopTablet'] = '30';
    $defaults['container']['paddingRightTablet'] = '30';
    $defaults['container']['paddingBottomTablet'] = '30';
    $defaults['container']['paddingLeftTablet'] = '30';
    $defaults['container']['paddingTopMobile'] = '20';
    $defaults['container']['paddingRightMobile'] = '20';
    $defaults['container']['paddingBottomMobile'] = '20';
    $defaults['container']['paddingLeftMobile'] = '20';

    return $defaults;
} );