im unable to use my media keys on my macbook

Perhaps your Mac's keyboard settings were changed to "Use F1, F2, etc. keys as standard function keys."

Refer to How to use the function keys on your Mac - Apple Support, under "Change the default behavior of the keys."

That's a valuable piece of information. It implies there is something installed on that Mac interfering with the behavior of those keys.

If you don't know where to begin determining what that might be, two options worth considering are System Information > Software > Installations, which reveals a comprehensive list of everything that was ever installed on that Mac: System Information User Guide for Mac - Apple Support

Since the amount of information in System Information can be overwhelming, you may find EtreCheck to be more useful. For instructions on its use please read Old Toad's User Tip, here: How to use the Add Text Feature When Posting Large Amounts of Text, i.e. an Etrecheck Report - Apple Community. Post its report in a reply to this Discussion if you would like some help interpreting it.

Restart your Mac normally (not "Safe Mode") before doing either of those things.

Apparently something else is interfering with their correct actions. Please determine if the same problems occur in "Safe Mode": How to use safe mode on your Mac - Apple Support.

The purpose of using "Safe Mode" is to determine if the problem exists in that mode or not.