lost my tool bar on my maacbook air

Not sure what MacOS you're using. In the current MacOS, Ventura, this is what you'd want to refer to:

Change Desktop & Dock settings on Mac - Apple Support

You'll see in this link how to hide/reveal the dock on your desktop.

IF OS is earlier than Ventura then go to System preferences, dock and menu bar pane to change the location and turn off "hide"