comfort zone

noun
1
a place or situation in which you feel safe or comfortable, especially when you choose to stay in this situation instead of trying to work harder or achieve more
منطقه راحتی, منطقه آسایش, حیطه راحتی
compare danger zone
2
a state in which you feel confident and are performing at your best
منطقه راحتی, منطقه آسایش
I knew if I could find my comfort zone I would be difficult to beat.