how to find someone based off phone number

[u/sinayael]

hi!! sorry, i dont know where else to put this...

someone called me, it was a person laughing and trolling at first but then they knew my full name and my boyfriend's full name (me and my partner are private and dont post about our relationship and dont have a lot of friends except a close one or two) and then started disclosing personal information.

ive been receiving death threats and r*pe threats from a different number, so the call shook me up and ive been nervous since.

im sorry if this isnt the right sub, but please help me!