It's a play I read titled "Father knows better".

setting: a fast-food restaurant:

Sean saw his father walk in and hide himself from him ...
father: I'm looking for the manager.
Manager: That would be me, sir.
Father: I'm Sam Thompson. My son works here.
Manager: Oh, you're Sean's father.
Father: Yes. It's his first job, you know. I just wanted to check that he's doing OK.
Mangager: Oh, fine. No problem.
Father: Hiring him was a good thing then?
Manager: Well, yeah, I suppose so.
Father: I'm sure he's a good worker but a typical teenager, if you know what I mean.
Manager: I wouldn't know.
Father: He's a good boy. And I assure you that if there are any subjects that need to be addressed, Sean and I will have a man-to-man talk.
Manager: I don't think that will be necessary ...
Father: Oh, no problem. I'm proud of my son. Very, very proud. And I just wanted you to know that I'll do anything I can to help him through life's dangerous sea.

The questions are:
1.  What are the funny words in the diallogue? I'm not sure about them.
2.  Why did the manager say "I wouldn't know"?  What did Father mean when he said "he's a good worker but a typical teenager, if you know what I mean."
3. Why did the manager give such a response "I don't think that will be necessary ". I just can't sense the humor here!

It's very very hard for a Chinese to understand the humor of English. I do hope someone can explain and help me understand a little about it. I'll be grateful! Thanks again!

first, in the restaurant.
maybe his son just a server or something like that...
so we can know not a dangerous work...

second, why his son hiding when he come?

Father: I'm Sam Thompson. My son works here.
Manager: Oh, you're Sean's father.
show this restaurant just one person the manager hire...

Father: I'm sure he's a good worker but a typical teenager, if you know what I mean.
Manager: I wouldn't know.
show his son just a child...
the manager is illegal

Father: He's a good boy. And I assure you that if there are any subjects that need to be addressed, Sean and I will have a man-to-man talk.
maybe just his son talk himself...(because the restaurant just one person....

Manager: I don't think that will be necessary ...
so the manager say like that

Father: Oh, no problem. I'm proud of my son. Very, very proud. And I just wanted you to know that I'll do anything I can to help him through life's dangerous sea.

this sentence just show his father don't know the situation about his son work and his father is a good father...
and we will find the joy...