Should you decide to buy your own web hosting, you can check prices at www.hostinger.ph
Domain name is your website address. Mine is digitalwithease.com. Other sites are google.com, facebook.com, etc.
SSL Certificate keeps your website secure. This is observed if your site address has padlock beside it. This also increases your legitimacy because you value the security of your website visitors.
(Example: You want people to find your website so they will know about your products and buy from your website. OR you goal is to showcase your photography skills so people will buy it directly from your website.)