First, prepare in advance - find out a little information from your interlocutor to keep the conversation going. Be interested and ask as many questions as possible.
Don't be afraid of pauses, they are natural. Instead of panicking, you can make a light comment about the situation or fill this awkwardness with a compliment. It is also useful to have a few topics for discussion in reserve, for example, movies or music.
Be friendly, smile and remain open. But the most important thing is to remain yourself, and not pretend to be someone else. If you feel awkward - humor or self-irony help defuse the situation.
The first meeting does not have to be perfect. You will have problems that most likely cannot be avoided. But this is normal, because the main thing is that you are satisfied with this meeting and want to meet again as soon as possible!