I cant log in to facetime

See If you get an error when trying to activate iMessage or FaceTime https://support.apple.com/en-us/HT201422 and

If you can't send or receive messages on your iPhone, iPad, or iPod touch https://support.apple.com/en-us/HT204065

And you can get Apple telephone support for help in solving your problem using this link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

Message activation error. 

Are you running any anti - virus programs? Using a VPN?

Try setting up another admin user account in System Preferences/Users & Groups to see if the same problem continues. Please post back on whether or not this worked. Also try the Safe Mode. Please post back on whether or not this worked.

Isolating an issue by using another user account    

Safe Mode - About.       

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor.  Please use copy and paste as screen shots can be hard to read. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown. If the log won’t post, try posting it in Pastebin and provide a link in a reply. After pasting the report in a PasteBin page, go to the top of the page, and copy the address in the URL bar. Paste that in a new reply.        Pastebin.    

Etrecheck – System Information.      

Web site version if required.  https://etrecheck.com