Go to Dashboard->Design->Website option, here you can change the Home page title, description, logo and favicon image.
In SEO section , update the Page Title, Page Description and Page Keyword.
Once you click on the Save button, the changes are updated and a validation message "Home page SEO saved Successfully".
Now move to Settings section to change the site Logo and Favicon image.
Make sure the height and width of logo image be 300px and favicon image be 16x16 or 32x32.
Click on the upload button to save the images.