Some prefer to buy the domain name and SSL certificate from their hosting providers. Especially when hosting providers offer free SSL and free domains for the first year.
Depending on your sites and what plans you have in mind, this may not be the best option. If you have several websites or e-commerce platforms earning you money, from a security point of view, it’s more viable to get your domain, hosting, and SSL certificate from different providers.
While the price you have to pay is higher, long-term it will mitigate potential losses. If something goes wrong with your hosting provider or you aren’t satisfied with their services, you won’t have to worry about your SSL certificate or domain name.
You can get the domain name from the likes of Namecheap or Namesilo; host your website with Bluehost, Hostgator, WP Engine, or any other top hosting company; and buy the SSL certificate from a specialized SSL Vendor.
SSL vendors offer the best prices on the market and a wide range of products. Since you have several websites, you may consider a multi-domain SSL certificate to secure them all under a single installation and save time and money in the process.