This is the 10494th most frequent Spanish word.
conviene
"It's suitable" or "It's advisable."
In this sentence, 'conviene' is used to express the idea that it is advisable or beneficial to perform the action of studying early.
Conviene estudiar temprano para aprovechar mejor el tiempo.
It is advisable to study early to make better use of time.
Here, 'conviene' suggests that reviewing the contract is a sensible or suitable thing to do before proceeding to sign.
Pienso que conviene revisar el contrato antes de firmarlo.
I think it is appropriate to review the contract before signing it.
In this case, 'conviene' carries the meaning of being in someone's advantage or convenience for a particular action.