Learn English – the word for somebody who does action/is action owner

This is a clear-cut situation fortunately. Using of is definitely correct here, whereas for is not correct.

"I am the owner of abc company"

Of takes the role of the possessive preposition here. This is evidently appropriate, since the person possesses the company in some respect here.

Certainly acquaintance would be my own choice, but perhaps you found something remiss with it.

You might further qualify it by saying something like casual acquaintance, incidental acquaintance, nodding acquaintance, or long-time acquaintance.

Of those, I rather like nodding acquaintance, since it implies that this is someone whom you would nod to in passing, but not pause and chatter at.