With "try" and "find" out is an unnecessary added word, you can just say try and find, if you are going to "find out" something you can just say "I will go find the answer" or "I will go find it" depends on what you are finding. 

For "listen" and "shut" it's kind of the same, you can just say "listen," adding the "up" could be a little more rude, it's more forceful and not as kind as "listen" or "listen, please."

The case for "stand" is just that it's a direction, you are standing up. But mostly if you are not doing some action, like standing or looking or something like that, then adding an "up" or an "out" is probably unnecessary.  

:D 

thank you a lot. now i know that it can give some rude expression

im also confuse shut and shut up..what the difference in this two words?

Hi. I am Cesar. I have want to know what do you think about these two words when it is added to some words... for example: try out find out listen up  stand up shut up i want to know i...

Okay, I found the place to edit.

listen up sounds like an amry sargeant talking to his squad. It is pretty rae otherwise.

I hope to hear from you.

Don