I haven't met before, and the only person my relatives are looking for is her phone number. Text or call first? Find out!

Of course, it is impolite to call before sending a text message.

It will be more natural to send a text message to chat first. There are more topics to talk about, and you can also think when expressing things. It's a little awkward to call.

So, texting is the beginning, then calling and asking her out.