I assume that when you tried to edit the text of a PDF "Gotham" does not appear in the drop down list of fonts. In most instances you do not have the font installed on your system.
Gotham Fonts by Hoefler & Co. are not standard fonts you would find in your system. These fonts must be purchased from the company website here: Gotham Fonts | Hoefler & Co.
Once you've completed your purchase. Download the font pack and install. The font should then be available in the drop down list of fonts on your next Acrobat restart. You can refer to this article here for installation: How do you install new fonts to Adobe Acrobat Pro XI?
Hope this information helps.