Is the email story I received true that there is a planned National Guard and military deployment nationwide that will enforce a strict quarantine keeping everyone at home for at least one week and possibly up to 30 days with all businesses closed, or is this only rumor?

This is only rumor. There may be deployment of National Guard forces for areas that might become problematic, particularly with respect to law enforcement issues when stores are closed and unprotected and law enforcement stretched thin. That is when predators will become greedy and seek low hanging fruit, to break in and loot, and serve themselves at the expense of shopkeepers who are not on duty. That is the purpose, not to keep people away from groceries or medicine at local pharmacies, so you need not worry about running out of food at this point in time.