Okay, so the movie that I cannot figure out was made in the 90s, I think, because I was a 90s kid. I remember watching it in daycare. But anyway... the movie took place near a carnival or circus and it had a boy in it too. I don't remember the plot or anything. Wow, that shows how much of the 90s I forgot.

The Carebears Movie that came out, like, late 80's or early 90's... it was set at a carnival and the main character in it (other than the carebears, of course) was a boy, is it possible that that's what it was?

How about

We're Back! A Dinosaur's Story (1993)

There is an evil Carnival at near the end, and an old scrawny man have captured the dinosaurs for his Carnival.

And of course there is a boy who is the main character, who came off the streets.

Like an animated copy of the one boy from 'Santa Clause the Movie'.