1995 Chevy Beretta wheel bearings?

1995 Chevy Beretta 40,000 miles

I noticed yesterday that when I was driving my car, it would make an inconsistent whistling noise toward the front of the right side of my car. While the noise is inconsistent because it doesn't do it all the time, sometime it's when I'm turning, sometimes just when going straight, but never when I am braking or at a complete stop. I checked my tire pressure initially because I thought maybe I had a hole in my tire and the whistling noise was air coming out of my tire but no hole was found, and my tire pressure was the same as it always is. I did notice that my front right tire hubcap thing was super dirty, while the other tires are all clean, maybe something is oiling right and something got rusted? I'm just trying to figure out what is wrong with my car and how much it might cost to fix because I don't have a lot a money. Thanks for your time!