Apache is an Open Source web httpd server.
Refer to Name-based Virtual Host Support.
Self signed certificates are for development only.
Use openssl to generate a new key and certificate.
openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout example.key -out example.crt
Two text files will be created, example.key contains the private key, and example.crt contains the certificate.