It is possible to create an unlimited subdomain with cPanel. In creating a subdomain you need to have your own hosting. So, you can access cPanel.
What is Subdomain?
A subdomain is a part of your website that may function as a separate website without the need for a new domain name. Subdomains may be used to generate memorable URLs for distinct parts of your site's content. You may, for example, create a subdomain for your blog that is accessible via blog.example.com and www.example.com/blog.
Step of Create an Unlimited Subdomain with cPanel
1. Login on cPanel.
2. Go to Domain > Subdomain.
3. Now enter your subdomain. i.e blog, product, etc.
4. Enable HTTPS Redirect by click on domains.