Font issue

Even though Acrobat can do that, you shouldn't do it, unless you have absolutely no other options. PDF files were not meant to be edited in such a way, and doing so is going to be difficult, annoying and possibly destructive to the structure of the file.

It's highly recommended you go back to the original file used to create the PDF, make the changes there and then create a new file from it. Or export the PDF file to an editable format (Word, InDesign, etc.), edit it and then create a new file, making sure to keep a copy of the original, in case you want to make additional changes in the future.

"I have Adobe DC ..."

Adobe Acrobat or Acrobat Reader?

No you don't.

If you have a paid subscription of Adobe Acrobat Pro DC you get access to all the necessary built-in editing tools that will aid you in customizing  a field object such as a text field, for example.

Adobe Acrobat also permits  integrating other Adobe image manipulation software or even external image editing programs, such as Microsoft Paint (if using MS Windows) to name another possible example.

Last, Adobe Acrobat Pro also provides the user with even more flexible ways  to change background, fill color, font color, and more, with Acrobat JavaScript.