Add a new instagram widget

Follow the instructions here.

Remove the "After First/Second Post" Sections From the Home Page

If you want to remove the "after first/second post" sections from the home page, do this:
1. Go to Layout and remove all the widgets from these sections.
2. Then go to Theme > Customize > Advanced > After First Post/After Second Post and make the background transparent and set the padding to 0px.
3. To remove the "Browse by Category" heading, go to Theme > Edit HTML > click anywhere on the code once (necessary) > press CTRL+F (or CMD+F on Mac) and paste this in the small search box that appears:
Browse by Category 4. And remove the text (make sure to remove <h2> and </h2> as well).

You can add widgets to these sections anytime and add background and padding from Theme > Customize > Advanced.