General symptoms of the flu:
"influenza (flu) begins abruptly, often with a fever over 100°f (sometimes higher in children and slightly lower in the elderly). Other classic signs and symptoms include dry cough, headache, muscle pain, chills and/or sweats, sore throat, and potentially severe, and persistent discomfort and fatigue. Sensitivity to light or other eye problems, and gastrointestinal distress may also be present.Symptoms may be severe for up to 5 days, and may persist up to two weeks"
not everyone may experience all of these symptoms however. Yes it is possible for you to re-catch a virus as viruses mutate all the time, one of the reasons they are so widespread and difficult to treat. The same virus can infect people in different ways yes as everyone reacts differently to the infection and has different levels of resistance.