Me and my gf used to be like that too. Both of us are reallllly quiet. We went out before but I decided to call it off and become friends. We got back together about two weeks ago and everything's been smooth sailing. If she has nothing to talk about, I just make something up. Talking about her shirt is better than having absolute silence.
I used to be really passive, and wanted her to be the active one in the relationship, but that would never happen. Once that hit me, I realized that I just have to initiate conversation and learn to be more open. Boost her ego, just keep asking her questions, and the conversation should roll.
Yes, it is better to be friends, then go out. It works a lot better this way and this is how most relationships are developed.