Keep in mind that you will be easily exhausted and you may want to start slow. Try to be out of bed and be active without becoming too tired. You can gradually work your way up to one or two daily activities in order to give your body a chance to fully recuperate.   You can begin with simple breathing exercises in bed. Inhale deeply and hold for three seconds, then release with lips partially closed. Work your way up to short walks around your home or apartment. Once this is not exhausting, begin to walk longer distances. Remember that while recovering from pneumonia, your immune system is in a weakened state. It is a good idea to protect your weakened immune system by avoiding individuals who are ill and by avoiding highly populated areas such as shopping malls or markets. Given the risk of infection, you should not return to school or work until your temperature returns to normal and you are no longer coughing up mucus. Again, doing too much can risk a reoccurrence of pneumonia.

TL;DR in Vietnamese:
Từ từ bắt đầu lại hoạt động thường ngày dưới sự cho phép của bác sĩ. Bảo vệ bản thân và hệ miễn dịch. Cẩn trọng khi trở lại trường học hoặc nơi làm việc.