This is the 3244th most frequent Polish word.
starać
To try; to make an effort.
Here, 'starać' is used reflexively ('się') to indicate putting effort into achieving something.
Muszę starać się, aby osiągnąć swoje cele.
I have to strive to achieve my goals.
'Starać' is used in the past tense to indicate that the parents made an effort in the past.
Rodzice starali się zapewnić nam dobrą edukację.
Our parents tried to provide us with a good education.
In this sentence, 'starać' is used with a reflexive pronoun to suggest an ongoing effort or habit.