I am hosting my webpage here. On my Google Drive. I want to purchase a domain name and point that domain name to the link above. Can I do that and how?
Yes it's possible, I would recommend a "frame redirect" since you don't want people to deal with the URL of the Google drive.
A Frame redirect basically keeps the URL as "mydomain.com" and you can still navigate around the site regardless of where it is being hosted.
Since you don't mention the domain registrar you plan on using I can't offer specific details on how to do it. However I use 1and1.com for my domains and their help pages explain how to set up a frame redirect pretty well.
Here is a better definition I found on their site of what a frame redirect is: "URL Masking or a Frame Redirect is a type of domain forwarding that loads the forwarding destination page while keeping the URL the same. To better explain, if the domain domain.com uses a Frame Redirect to http://www.google.com/ then when anyone views http://www.domain.com/ in the browser, they will actually see the Google page, while the address bar will still show http://www.domain.com/"