I think texting is a blessing in disguise for a very quiet INTP trying to get to know someone slowly. Text away! Make her laugh. Say goofy stuff. Show the confidence that you say you have. I'm the same way. Through text and other forms of writing I can express my true self much better. I can easily say what's on my mind because I have time to think it through.
Use your humor and show off your Ne through text messages. Maybe you even want to just text her for several weeks before even hanging out. If she's an extrovert that is eager to hang out or if she's a J and wants a decision made, this might not work. But, this can actually work in your favor with certain types as it shows that you aren't in a huge rush - that you're patient.
Main thing is just be real. If she's pushing you through text messages to go out and you're not quite ready to hang out in person yet, just say something like, "If I wasn't such a slow mover, we would have already gone out. But, we will go out sometime, and it will be worth the wait. We'll do something really fun."
Just be straight up with her. Don't rush yourself and don't become someone you're not. In the meantime, do use your wit to make her laugh and get to know her at a comfortable pace.