why my air mac not has key note

You can quickly download Keynote, Pages, and Numbers for free through the blue App Store app on the application ribbon at the bottom of your Macbook Air screen. Open the App Store, type Keynote in the search bar, and you'll see Keynote listed there.

LearningAgent

You can download Keynote from https://apps.apple.com/gb/app/keynote/id409183694?mt=12

You can only delete unwanted large files or get your internal hard disk upgraded