In the United States, freedom of speech and expression is strongly protected from government restrictions by the First Amendment to the Constitution. This constitutional right of free speech only prevents government restrictions on speech, not restrictions imposed by private individuals or businesses unless they are governmental institutions acting on behalf of the government.
Many laws exist to restrict the ability of private businesses and individuals from restricting the speech of others, such as employment laws that restrict employers' ability to prevent employees from disclosing their salary with coworkers or attempting to organize a labor union. These laws are not the First Amendment and these protections are not imposed by the First Amendment.
In summary, if you're not in jail or being arrested, then your First Amendment freedom of speech is probably not being infringed.
Does this mean you can say anything you want? Anything at all? Well, sort of. You see, I have the right to free speech too, and I can tell you to get stuffed, or kick you out of my store for acting like an ass.