Is it better to text or call her?

Text messages allow you to carefully craft your messages, but they atrophy your ability to make spontaneous conversation. Making calls isnt just good practice for talking comfortably on the phone, but strengthens your ability to make unscripted conversation in general.

Is it weird to ask a girl out over text?

Texting can be relaxing and should be used for casual communication only in dating or relationships. While asking a girl out over a text is easy and works great, it can be misleading because there is no tone. Make all texts clear and try to avoid asking any open-ended questions.