Hi there, the area to the right of the post content is for the Featured Image set on that post. If you do not have a featured image set, then that space will be blank. See the demo page for what the blog page on Dyad/Dyad 2 would look like with more posts and with featured images.
If you are not planing on making blog posts, what I would suggest is to create a page for your home page and then go to Settings > Reading and set that page as the static front page.
If you are going to create posts and want those posts to show on the main page of your site, then when using Dyad, you will want to add a featured image to each post. If you do not want to use featured images, then I would suggest using a different theme that does not rely on them for the layout.
