It sounds like your AirPort Utility is not detecting your AirPort Express, and you have a blinking amber light for the extenders. I found some resources that I think might help with this.
First, I recommend verifying you have the latest version of AirPort Utility. The latest version on the Mac resolves an issue where AirPort base stations may not appear in AirPort Utility. You can find the latest version for the Mac here:
If you have the latest version and are still unable to see your devices in AirPort Utility, I recommend the following resources:
Once your device is seen by the AirPort Utility, you can follow the steps in the article below to address the blinking amber light:
Wi-Fi base station: Understanding and resolving a blinking amber status light
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