my bluetooth isn't working on my mac. How do I reset it or uninstall it?

Have you visited System Preferences > Bluetooth and enabled it, so this menus extra icon is active and your Mac is discoverable? Did you install any third-party software related to Bluetooth, or accompanying any third-party Bluetooth devices?

if it was me then I would first try to reboot the mac

and if it was still a problem then I would try

How to reset NVRAM, PRAM, SMC on a Mac | Macworld