Blogger is the most known free subdomain creating platform. Blogger is part of Google. if you create a free blog it comes with .blogspot.com extension. anyone with a g-mail account can easily create a free blog on blogger. but if you create a free blog visitors not gonna believe or trust you most. but may some exceptions there, some free blogger blogs get more traffic and earnings?
but I suggest you create a TLD custom domain for the blog. what is TLD-Top Level Domains ex: www.example.com, www.example.net like domains. you can register a domain with your famous domain registrars. you may ask why should I buy a custom domain, a custom domain represents a seriousness in blogging, most of the people trust custom domain names comparing to free Blogspot sub-domain. follow below steps to host custom domain on blogger:
This process may look complicated but it is not
add A record from google DNS. like below image ADD > Select > A, Enter Host as @ and points to as 18.104.22.168 and save. you need to add three more A record as like below image.