Editing your Profile
In order to edit your profile content go to your profile page (There is a link to your profile in the drop-down menu that appears when you click on your profile picture in the navigation header at the top of any Couchsurfing page).
Once on your profile, click on the Edit Profile button.
Once you click into Edit profile, you will see your Hosting Availability and fields to edit the rest of your profile content. There is also a "My Home" tab where you can edit your hosting information and preferences.
Edit your Account Settings
To edit your account settings please, click on "Account & Settings" link in the drop-down menu that appears when you click on your profile picture in the navigation header at the top of any Couchsurfing page. Here is a direct link: https://www.couchsurfing.com/preferences/account
After you click on "Account & Settings" you will see a page where all of your general data can be edited and a panel on the Left side of the page where you can click to edit other settings.