Signs of flu can include high fever and chills, rapid onset of cough/sore throat, tiredness, headaches, and body aches, with the illness often lasting over a week.
If you have underlying medical conditions such as asthma, diabetes, lung/heart problems, or another chronic condition, make sure that you receive the flu vaccine and seek medical care early if you get the flu.
If you are generally healthy, treatment for the flu consists of rest, good nutrition and hydration, and use of acetaminophen or ibuprofen when needed for symptoms. For more on taking care of yourself if you get the flu, read https://www.cdc.gov/flu/treatment/takingcare.htm
Practice good hand hygiene and cover your cough to reduce spreading the flu. If you are sick with the flu, especially with a fever, contact your instructors to see if they advise to stay out of class until you are improved. The Center for Disease Control recommends that people with the flu avoid returning to work or school until their fever has resolved for 24 hours.
You need to seek medical care for the flu if you develop problems such as impaired breathing, can't control your fever, or if you can't walk, eat, or drink adequately.
Want to reduce your chances of getting the flu? Get vaccinated, practice good hand hygiene, get adequate rest, maintain a healthy diet, and exercise regularly.