How do a make a test call?

Hi, there. I would like to know if I need a termination service provider to make a test call, or if there is any provider that allows to make test calls. I’ve just installed Asterisk on a computer with a TDM400P card (1 FXO, 1 FXS for now) connected to a PSTN line. I can hear the Asterisk demo when I call from my cellphone to the PSTN phone number. The idea is to setup a small prepaid phonecard business, and I just want to place a long distance call to test before I go over the IVR and billing software. I’m new to Asterisk.

Thank you in advance.