I found this expression in the internet and I would like to know its meaning
Champ is short for champion, the winner of a contest. Literally taken, it's congratulatory --
You've shown them that your performance is the way to go to demonstrate the qualities of a winner.
Check out this greeting card, complete with winner's trophy and inscription.
But taken ironically, it means just the opposite, i.e,
You're no champion and you've shown the way to go to defeat.
Here's a scene from A Scary Scene in a Scary Movie by Matt Blackstone. The narrator is trying to maintain his calm, fails to do so, and is mocked for his failure.
I unclench my teeth and tell my body not to do anything stupid. It doesn't listen. When I hold out my drinking glass for my mom to refill, I tell my fingers not to but they do it anyway: they relax, and let go.
The glass clanks on the table as water seeps into the white tablecloth.
Way to go, champ." Phil laughs.
There's no way to tell which without the context.