I think you are   
>! a human heart  



I am seen in darkness and in light
>! In light during an operation. Darkness via one of those machines which hospitals have.

I am calm yet tend to fright.
>! Explanatory.

I can be quiet, I can be loud.
>! When you're scared your heart beats louder.

I hide in shame, yet am so proud.
>! It's common saying that your heart feels (technically it doesn't but still). At times you feel good about yourself and at times the it's the other way around.

I can be different, but still the same,
>! Different health conditions but same functionality.

I am straightforward yet am playing games.
>! Nothing solid but here goes. Your heart wants to do things that are fun and wants to avoid work?

you can easily find me,
>! You just have to look within. (probably finding what you love)

but you'd have to look and see.
>! You have to look within :) 

I am found every where I know,
>! Hearts are pretty common. Might also be referring to love :)

but why is it sometimes not so?
>! People being greedy, cruel or mean?

so many things that I can make,
>! If you're heart is set to something, you can do so many wonderful things.
 
but how many tries will it take?
>! Not quitting and sticking to your goal.