i heard my(white) boss call my co-worker a hoodlum. I also heard them say hire more white people. Is this discrimination?

If you heard your boss say to hire more white people, this is clear evidence of discrimination based on race. This could give rise to a claim by any black employee who applies but who is not hired and could potentially be used as evidence to support a claim involving other discriminatory treatment of black employees in the workplace, including the name calling your described. If you want to know more about how to file a claim of discrimination, you can go the EEOC website.