In Site -> General -> Store Address, you could update your store name and address. Store name and address are used in various places such as Contact page, Order Invoice etc. Click "Save" button after you have done the change.

Site Email Address is main contact email address for your site. In Store -> Configuration, you could add email addresses which receives the copy of order confirmation email.

In Site -> General -> Logo upload your site logo to the server.

In Site -> General -> Meta Tags add meta tags to your web site. These tags will show up in all the pages. Click "Save" button after you have done the change.

In Site -> General -> Miscellaneous, you could further configure some settings. Click "Save" button after you have done the change.

Here is the description about these settings.

1) "Use Dedicated SSL Certificate"
Check this box if you have a SSL certificate installed. All the pages that need secure transmission to server will be using SSL. These pages are login page, register page and checkout page etc.