I saw a girl I didn't know in the university study room and liked her very much. I don't know how to know her, and I don't know how to say the first sentence.

The polite kind! But don't say anything the first time! Don't ask people where they are from or their phone numbers. It's best not to ask anything, just leave a slightly better impression.

Then gradually get familiar with it, you can sit closer to her and study together! Then slowly, there will be more opportunities. . . .

Haha, step by step!