This is the 14345th most frequent Russian word.
открываем
"Открываем" means "we open."
The word 'открываем' is used here as a present-tense verb to describe the action of opening a physical object, the window, performed by the subject 'Мы'.
Мы открываем окно, чтобы впустить свежий воздух.
We are opening the window to let fresh air in.
In this sentence, 'открываем' figuratively represents beginning or unveiling something new as part of a metaphorical expression, attached to 'новую страницу своей жизни'.
Каждое утро мы открываем новую страницу своей жизни.
Every morning we turn a new page in our life.
Here 'открываем' is employed to denote the act of discovering or revealing information or properties, applied to 'свойства веществ'.