How can I change the title of the site on Google search?
Meta Tag

The Metatag module allows you to automatically provide structured
metadata, aka &quot;meta tags&quot;, about a website. In the context of search
engine optimization, when people refer to meta tags they are usually
referring to the meta description tag and the meta keywords tag that
may help improve the rankings and display of a site in search engine
results.

Basically it allows you to format your title and description that gets indexed by search engines.
Once you install it, you need to override the Global: Front Page and remove the [site:name] token.
Here is a Video Tutorial
PS: You will need to wait until Google crawls your site again to see changes.