Generally, yes it means that in interactions with the government, there is more of an obligation for a citizen to speak English, rather than for the government to provide services in multiple languages.
It doesn't affect Taco Bell because that's a private corporation. And it doesn't affect transportation because that's also intended for travelers, visitors, etc. Nor would it affect health care.
But a good example would be driver's license exams. California offers those in 32 languages. Almost all states offer them in at least 2. If English is made the official language by legislation, there would be a strong argument to only offer driver's license exams in English.
Well, even more precisely: an executive order applies to federal workers in the executive branch. It doesn't apply to federal workers in the legislative, or judicial branches, and other sorts of workers. It certainly doesn't apply to private citizens or the states.
It doesn't affect Taco Bell because that's a private corporation. And it doesn't affect transportation because that's also intended for travelers, visitors, etc. Nor would it affect health care.
But a good example would be driver's license exams. California offers those in 32 languages. Almost all states offer them in at least 2. If English is made the official language by legislation, there would be a strong argument to only offer driver's license exams in English.