REALLY ITS YOUR CHOICE
some people like to have pups, some like them to have a first season and some to get them spayed before the first season.
if you dont want to breed them then spay them, pups are very hard work and timely.
and no it doesnt matter if they have had a season or not they still grown up the same its just the vets say oh its better if they hae a season and then some say its better if they dont.
i looked after dogs done both ways, before and after and they all behave in the same manner.