The odds are pretty good that if you have cough, a sore throat and a stuffy nose, you have a viral infection. Both the common cold and influenza are caused by viruses, although these tiny organisms also cause everything from herpes and HIV to measles and Ebola. Obviously, some of these viruses do cause medical emergencies; Ebola, while rare, is deadly. However, the common cold isn't rare or deadly, and despite how sick you feel, there are no cures for a cold. It'll be over in about a week.
Unlike bacteria, which are single-celled microorganisms that are able to replicate on their own (the microorganism divides itself into two through a process known as binary fission), viruses bum what they need to reproduce from you or else they die. And, at the very basics of things, this difference is why antibiotics are effective against bacterial infections yet not against viruses. Viruses can be difficult to treat because, unlike bacteria, viruses actually live inside the cells of your body. The best that can be done against a viral infection is to ease the symptoms, usually with fluids and over-the-counter pain relievers. Unless symptoms are severe, such as a high fever or difficulty breathing, this is a treatment plan your primary care doctor can make. (And, if it turns out to be a bacterial infection, your primary care doctor can also help treat that, usually with antibiotics.)
Vaccinations protect against some viruses, such as measles or smallpox. Some viruses, such as HIV and herpes, can be treated with a prescription from your primary care doctor for antiviral medications, which work by interrupting the reproductive ability of a virus.