Hi there,
that ‘section’ is within a Group Block which gets its padding from the Customizer > Layout > Container – which has 80px top and bottom.
Do you need the group block?
If you do then edit the Group Block, and on the Settings Sidebar > Advanced give it an Additional CSS Class of group-padding
and then you can use this CSS to adjust it:
.group-padding .wp-block-group__inner-container {
padding: 20px 20px 20px 20px;
}