This idiom or expression has to do with:

Having an injection.

A. Have you got your shot yet?
B. I’m not going to. I don’t believe in getting flu shots!!

This idiom or expression means:

Some chance.
An opportunity.

Give him half a chance. Take it easy on him.

This idiom or expression like phrase means:

A chance.
An opportunity.

They deserve the opportunity to prove themselves. Give them a fair shot.

This idiom or expression has to do with:

Finding an opportunity.
Using or creating an opportunity.

A. Are you having any luck getting your book published? I know have it ready
B. I don’t know anyone in the business. If I could only get my foot in the door!

This idiom or expression has to do with:

Being too late.
Missing an opportunity.

Hey, make a decision or you’re gonna miss the boat.

This idiom or expression represents:

More opportunities.
(Usually used in order to sympathize with a girl or boy who has been hurt romantically.)

Don’t worry. There are plenty of other fish in the sea. There will be other (romantic) opportunities.