In WordPress Dashboard go to Appearance submenu and click on Customize.
After clicking on customize you will in theme Customizer.
Here you have to click on Front Page Section than Gallery section
In Header Here you can Change Title & Description
Go to Customize -> Frontpage Section -> Gallery Section -> Header
In WordPress Dashboard go to Appearance submenu and click on Customize.
After clicking on customize you will in theme Customizer.
Here you have to click on Front Page Section than Gallery section
In Content Here you can Change Content & Icons
Go to Customize -> Frontpage Section -> Gallery Section -> Content
You have to use Gallery Image Size 520Px X 480Px