Hi Shifty,
Great job on asking her out and congratulations.
It is best to have a combination of texting and calling.
At these early stages, it is best to text most days and call perhaps once or twice a week.
So, in the beginning, you may be doing about 80 percent texting and 20 percent calling.
However, as time goes on and the both of you are getting to know each other better and going out on more dates, the percentages should become more balanced out so that there is a relatively even blend of the two.
You shouldn’t ask her, “On which day do we meet?”
Yes, that is not confident enough.
You should just give her a day and time.
If that doesn’t work for her due to her schedule, she will let you know or even volunteer a different day and time that works best for her.