Do you know if i'm allowed to use bee and puppy cat music like puppycat singing for the background music in a youtube video? if I put all credits and everything.

We can’t grant permission for a bunch of reasons. We are sorry, but you can buy Oliver, the vocaloid that is used to make PuppyCat’s voice, and make all of your own “puppycat” singing if you want. 

http://powerfx.com/products/oliver