CNAME file for my github pages site is not working

I have set up my cname file so that my mattmaginniss.github.io is being displayed as matthewmaginniss.com.

I followed the instructions carefully and the settings tab says that my website is being published at http://ift.tt/17KqqhN so yay!

So the next step says "Configure DNS settings"

After you've created and committed your CNAME file on GitHub, do one of the following with your DNS provider: If your custom domain is a subdomain (recommended), configure a CNAME record.

If your custom domain is an apex domain, configure an ALIAS, ANAME, or A records.

This is where i am stumped, I don't know who my DNS provider is, i don't even know how to figure that out. I've been dealing with this for a few hours, and googling tirelessly has left me empty handed and lacking answers.

p.s. plan to redirect my domain mattmaginniss.com purchased with google domains to redirect to this website. If that gives you anything that can better help you in helping me, I'd like you to know. Thank you for any help you have to offer.