(a)DDL_004_Basic Search Optimization
It is a good idea to play nice with Google if you want to have any hope with search results. Verifying your domain with GSC is a small but important part of that.
To verify my domain ownership with Google.
The above, but with more time consumed due to an issue with the site’s nameservers. It may not be a problem for you depending the way you build your website.
1-2 hours (due to the nameserver problem). It should be about 15mins if you know what you are doing.
Google search engine will require you have access to your domain’s DNS settings, so if you don’t know what that is, find someone who does :)