I don't know about it
Je n'en sais pas tant que ça sur toi.
I don't know that much about you.
I really have no idea.
I have absolutely no idea.
Je n'en sais guère à votre propos.
I know very little about you.
Je n'en sais guère à ton propos.
I know very little about you.
Je n'en sais guère à votre sujet.
I don't know much about you.
I have absolutely no idea.