Step 1: Go to Admin Panel, then Appearance and Click Widgets
From there you can set WP Travel Engine Sidebar, Right Sidebar, Footer 1,2, and 3.
No simple drag and drop the widgets from the Available Widgets to Right Sidebar, Footer 1,2 and 3. After adding, you can see the sidebar in a single page whereas Footer widgets in the front page.
Or you can also add Footer Widgets from customization options.
Go to admin dashboard|>Appearance>Customizer>Widgets
Click on each footer and add widgets.
Suppose, here we have add Categories, it looks like this,
Repeat the same process in Footer 2 and 3 widgets as well.