Hi there,
1. you can add some Top Padding to the Csutomizer > Layout > Container.
If you want to keep the sidebar with no gap then you will need this CSS:
@media(min-width: 769px) {
.is-right-sidebar {
margin-top: -20px;
}
}
Adjust the -20px to suit the top padding you added.
2. You can adjust the Content Separator spacing in Customizer > Layout > Container.
OR use this CSS:
.post-image-below-header.post-image-aligned-right .inside-article .post-image {
margin-top: 1em;
}