Here is how you can change defualt store view name,Web site name

1.Login to your magento2 admin panel.

2.Click on Stores on left panel

3.Click on “All Stores”

4.To change “Default Store View” name click on third column “Default Store View” and Change Name field and save.

5.To Change “Main Website Store” click on Second column of Stores set name field and save changes.

6.To chnage website name click on first column of stores , Set Name and click “Save”

Thats all please do not change code.This will break your site.

See Visual demonstration on bellow video