how to make power point presentation on Macbook air

You can make a PowerPoint on your MacBook Air by downloading the Microsoft PowerPoint app from Microsoft, or by downloading Microsoft PowerPoint on the App Store. You can also create a PowerPoint by using the Keynote app that comes with your MacBook Air. Just create the presentation as you would, and if you need a PowerPoint-compatible file, you can create one by going to File -> Export to..., and clicking PowerPoint.

In addition to bumbleben0's answer: you could also download for free LibreOffice for Mac https://www.libreoffice.org/get-help/install-howto/macos/