copy of my contact numbers to my pc

That all depends on what kind of account your contacts are stored in. If they are stored in iCloud, see here:

Import or export a vCard in Contacts on iCloud.com - Apple Support

If you're using something different, such as Gmail or Exchange, you'd need to look at their help documents.

There are apps on the app store that will allow you to export contacts - or contact groups - in VCF format which you can import into the program on your pc.

Or you can use iCloud.