You can change the name of your website from your Admin -> Settings -> Basic Information section. You just need to enter a value in the "Community Name" Field.
Website Browser Title
You can change the browser title of your website from your Admin -> Settings -> SEO section. Place your browser title in the "Global Browser Title" field.
Website Domain/Sub domain
Check here for our guide on adding a custom domain.
Check here for our guide on changing your Enjin sub domain.