How to edit a a blog page and post page?
Possible Answers to Your Question:
Go to Layers > Customize and browse to this page in the preview pane. Once loaded, you should see an Edit Layout tab. Under that are the widget areas on this page, such as the Sidebar and Footer panels. You can add and remove widgets there.
To change the layout or look of your blog page, you need an extension like Layers Pro, which lets you change things like image ratio, what meta is shown, etc. You can also change it with a child theme (browse Layers > Marketplace) or make your own customizations:
The sidebar layout can be changed in Layers in the Customizer under Blog > Archives