when to start thinking of names

not sure of the gender yet havent been able to get checked due to insurance. but when do you start picking a name. i wouldnt even know where to begin like my boyfriends last name is Vasquez and if its a boy im not sure if he wants to pass his name down for a third generation or if he wants tp pick a name. i feel like we are going to wait last minute and hes going to be tasked with picking a name which im not too sure about lol. cant think of any names i like that go with the last name or names in general