Does anyone knows how I can find out how much a certain person makes or file on their taxes, or have assets?..

Question

...or if they are in a corporation?

Answer 1

You can ask them

Answer 2

Is not and should not be available to anyone. However, if there is fraudulent activity a government can ask for a warrant, issue that warrant and the information must be given to or made available to them.

Answer 3

Nowhere.  It is private information you're after, it cannot be revealed to the public unless the person involved agrees.

As for a corporation, a public company has to file financial information quarterly, but private companies are just that: private.

Answer 4

There is no legal way for you to find out what another person files on their Income Tax Return.