I will try to simplify the explanation of the effects caused by the novel coronavirus. At first, when the virus enters your body, it can stay there up to 14 days without you showing any symptoms of illness. This is the incubation period for the disease COVID-19 which is caused by this virus. After 14 days, you are likely to show some symptoms like cough (dry), fever, tiredness and in severe cases, difficulty in breathing (in this case, you need medical assistance). If your immune system kills the virus up to an extent, you will recover soon without any medical care, however, you should keep yourself isolated from the time you feel the symptoms till you test negative for coronavirus. In case, your immune system fails to tackle the virus, then it will attack your lungs rapidly and can lead to pneumonia in which most of the people need ventilators. People with weak immunity are at most risk from COVID-19.
Just follow the instructions given by the government of your country for now and stay safe at home. Stay awesome!