You've secured a date, congratulations. But your having insecurities about starting a stimulating conversation. No doubt even if you've conversed online or in another context, the dating context is itself a potential minefield. Here are someways to ensure a free flowing conversation on a first date.
You want to open conversations with no dead-end questions. Keep them open to long and detailed responses. By doing this, you can add to it, bounce off their input and be better placed to keep the ball rolling. These can also develop into other topical discussions which can go on and on. Yet try to keep discussions and debates in check, otherwise these can turn into arguments.
Topics have to be relevant. So previous relationships are an obvious no go area, but you'll already have things in mind. Remember how and why you first started chatting. Something must have sparked. You just have to apply it in a face to face context. Just try not to over exaggerate or overstretch yourself by telling too many elaborate stories. Conversely, don't talk in soundbites or in a monotone manner.
There's a unique personality they want to see as well as a pretty face. Listen carefully, think before answering back and assume an air of authenticity, and you've got this....and possibly a second date.