First, you would not buy the software. You pay for a license to use the software. You may continue to use it only as long as you continue to pay Adobe. You stop paying, the software will stop working.
Fonts provided through the Creative Cloud apps are available only through Typekit. There are limitations to their use, so you should read up on Typekit before spending any money.
It looks like Century Gothic comes with Windows OS. I'm guessing you are on a Mac?