Keep it honest. Talk on the telephone and continue to learn more about your correspondent. A phone call can reveal a lot about a person's communication and social skills. It is worth the cost of the call to protect your security. But do not give out your phone number to a stranger.
Trust takes time to develop.
Only when you feel completely comfortable should you furnish your phone number. Don't rush into anything. Meeting someone online and then arranging a date in a relatively short time can be dangerous. Take time to find out who this person really is. If someone is pressuring you to get together before you are ready, this is another warning sign.