How to tell if motherboard has bluetooth?

Assuming you're running Windows, click the start button, and then search for "Device Manager" (or open CMD or PowerShell and type devmgmt.msc). Look at the list of devices. If Bluetooth is there, you have it; if it's not there, you don't. Alternatively, run CPUID CPU-Z to determine the exact model of your motherboard, and then Google the specs.

Idon't have a single clue tbfh

You forgot to add the possibilities. we don't know the options from which to choose.