On reading jokes I came across some, which I couldn't comprehend
Can anyone help me figure it out?

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What do you call a girl with one arm and one leg?...EILENE.
What do you call her if you're Japanese?...IRENE.
What do you call an Irish man w/ no arms and no legs and bouncing around
the room?...Rick O" Shea.
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These two guys walked into a bar... you think the second guy would've
ducked!!
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Knock knock. Who's there?
Jupiter. Jupiter who?
Jupiter hurry or you'll be late for school.
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Man: My wife's leaving for the West Indies.
Friend: Jamaica?
Man: No. It was her own idea.
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I would be grateful for any help!
Thank in advance!