Lets say I find a font that I want to use commercially. Where do you purchase a license for said font? Is there a specific store or clearing house that is legitimate?

Typically there is information about use from where you download the font pack. This usually includes any limitations or prohibited uses.

It is up to the creator or distributor (like Adobe) to set the terms of use.

There are a lot of fonts with open font licenses. Adobe fonts and other sites let you do an image search where you drag an image of the font in the search bar to find an equivalent. You may find something that matches and is free.

Adobe Fonts
https://fonts.adobe.com


Not 100% sure where the question stems from. If you pirated a font and now want to use it commercially, go back to the source and purchase/register it for proper use.