difficult sentence

hi all in theses sentences

Please, sit. Why don't you enjoy a cup of calming jasmine tea?
I don't want you to get too excited over nothing.
what is the meaning of over nothing
This will be over quickly.
please what the meaning of over quickly (i know quickly)
You're really gonna hand over the Avatar for a stupid piece of parchment!?
please what is the meaning of hand over

thank you

Over nothing: for no reason, because of a very small problem.
Over quickly: finished quickly.
Hand over: give something to another person.