Where to Get Fonts Before Editing Slides or Presenting a Webinar
Ask to know which fonts were used for the creation of the keynote presentation.
Before presenting, these must be installed on your computer.
If fonts are missing, when the keynote is opened, a small message box will appear on the top right saying "Missing Fonts."
Missing fonts will cause formatting issues such as text getting cut off or incorrect spacing.
Use Finder to go to Applications.
Click on Font Book.

See which fonts you already have.
Currently for new keynote presentations we are using the two fonts Open Sans and Oswald. These are the two you need to have.
(In the recent past we used Bebas Neue, so this one is also good to have if you will need to use an older presentation.)
This is what your Font Book needs to have:

If you don't have Open Sans and Oswald fonts, you can get them for free.
Download & install, then move them into your Font Book.
OPEN SANS font can be downloaded from: https://www.fontsquirrel.com/fonts/open-sans

Click on downloaded file to open it. Find it in lower left of your screen.
Click to open and move it into your Font Book.
OSWALD font can be downloaded from: https://fonts.google.com/specimen/Oswald
Click Select this Font.
Click Download in Family Selected section.

Click Save.

Click on downloaded file to open it. Find it in lower left of your screen.
Click to open and move it into your Font Book.
You are done. Great job!