What does sartre call the idea that people should only be concerned with what they can control or what directly affects their potential to act?

Despair

Despair, in Sartre's philosophy, refers to the attitude that the existentialist takes when observing the things that are beyond his control. It is the realization that, whatever our plans might be, they might be thwarted by other people and external events. Therefore, the way in which we face the world is one of indifference. We try to control our own actions, while realizing that the external world does not submit to us. We cannot rely on anything that is outside of our control.

yjtukytunthry yt? h4jt but tut ukun buy

this would be in the imperative mood. it is a category of verb forms that are used to express orders,instructions,commands or requests.