Talking on the phone?

I am really not confident when it comes to phone calls. Ill explain why.. Basically because I have no confidence, my stepdad gets me to answer calls and stuff. But they are never for me and I never know what he wants me to say to people, which makes it a really awkward phone conversation. What I want to know is, is this why I'm still not confident on the phone? I mean if someone rung me up and asked questions that I could answer, that were about me, it wouldn't be so awkward. So am I not confident because each awkward phone call I have to answer just makes me less confident each time?? I'd like to be more confident on the phone.