I definitely couldn't start calling people until I had gone to a couple meetings and gotten to know them a little better. My first sponsor had me call 5 women when I was on my second step, to get their concept of a higher power. It helped me learn how to pick up the phone, and made it easier to use the phone when I was feeling squirly. I eventually fell into a niche of women, and those were the women I called. There were a couple friends I made, and we'd talk nearly every day. But it did take some time to feel comfortable, especially when its a stranger. When you go back to the meeting, tell them you thought about calling but were uncomfortable. I'm sure they'll tell you they felt the same way at first. Its just nice to get comfortable with the phone, so that if you feel like drinking, you pick up the phone instead of a drink.