To print a check, you have two options. You can navigate to the Other Reports tab and choose "Print checks" from the report list to the left. For more information on this report, please visit this article.
Or you can use the drop-down to select Print checks, among other options, under Actions in the Favorites section to the right of any of your grid views (note: this section is "collapsible". If it has been hidden from view to give more screen space to the grid, you can bring it back by clicking the star icon in the upper-right. See this article for more information on the Actions drop-down in the Favorites section.