In this documentation, we can check how to change store title in Magento.
1) Login to Magento admin panel.
2) Go to ‘CMS’.
3) Click the option ‘Pages’.
4) Select the page ‘Home Page’.
5) Go to the option ‘Page Information’ in the left panel.
6) Change the title in the section ‘Page Title’.
7) Click the button ‘Save Page’.
That is how we can change store title in Magento.
If you need any further help please reach our support department.