This is the 11717th most frequent Russian word.
завести
"Завести" - to start, to acquire, or to bring (depending on context).
In this sentence, 'завести' is used to indicate acquiring or starting to have a pet, specifically a dog.
Я решил завести собаку.
I decided to get a dog.
Here, 'завести' is employed to mean starting or initiating an operation, in this case, of a car.
Он помог мне завести машину.
He helped me start the car.
In this context, 'завести' is used metaphorically to indicate initiating a discussion or conversation.