You have 4 types of viewing modes in your workspace:

How to switch to the Grid View:

Access the views dropdown from the top left corner of your workspace:

The Grid view is the place to plan and preview your Instagram posts.

Strategically plan and schedule your content by drag and dropping posts in your grid view, visualize it for all the content you have in advance, and see everything at a glance to perfectly organize your Instagram account. 

Once posts are in the perfect order, simply make sure to schedule them accordingly. You can always double-check by sorting posts as "Last scheduled"