The attention is inside and outside. You open to the outside right from the beginning.
You increase the exchange of qi between your body and your surroundings. During the exercise you gather additional qi and store it in your body.
Even if your body is not in a good condition and you have little energy, you can improve your health condition with the exercises.
As you did already open yourself, there will be qi reactions from time to time right from the beginning. These side effects are easier to deal with, also suitable for sick persons.