My url bar has gone missing on safari

To edit your tool bar in Safari, right click (Control key + left click) at the top of the browser just below where the Menu Bar is. A context window will appear next to your cursor that says Customize Toolbar... --click that

A drop-down window will appear showing you all the tools you can modify. If you just need the URL Smart Search box, grab it with your mouse cursor and place it wherever you'd like. There's lots of choices. Otherwise for easiness, you can just drag the default set back into your tool bar and start over.

Here is a support article with more information: https://support.apple.com/guide/safari/customize-the-safari-window-ibrw1012/mac