Safari has an icon that resembles a blue compass.  Click the Safari icon in the Dock at the bottom of the screen to open Safari. It's in the menu bar at the top of the screen in the upper-left corner.  This displays the Safari menu. It's the third option in the Safari menu.  This opens the Preferences menu. It's below the icon that resembles a blue puzzle piece at the top of the Preferences window. All extensions and ad blockers are listed in the menu to the left in the Extensions menu.  Click to remove the checkbox to the left of all enabled ad blocker extensions. To enable the ad blocker again, navigate back to this menu and click the toggle switch to enable the extension.

Summary:
Open Safari. Click Safari. Click Preferences…. Click the Extensions tab. Click the checkbox  next to all enabled ad blockers.