"我跟你不熟" 的英文怎麼说?

I am not so familiar with you.
I know little about you.
I don't know well about you.

I'm not familiar with you,so why should I give you my phone number?

We haven't known each other
so why should i phone you

You're not my acquaintance, why should I give you my cellphone number/telephone number?

We don't know each other 我们不熟