Instagram

You need find some information

Instagram ID

https://smashballoon.com/instagram-feed/find-instagram-user-id/

or

https://codeofaninja.com/tools/find-instagram-user-id

Client ID

http://help.dimsemenov.com/kb/wordpress-royalslider-faq/wp-how-to-get-instagram-client-id-and-client-secret-key

Access Token

http://instagram.pixelunion.net/

Go to Manager panel > Storefront > My Themes > Customize > Homepage > Instagram

Change the value of "Access Token", "User ID" with the information you have get and Save & Publish.