Parasites are a natural part of life.
In a perfect world, with perfect animals and perfect feed, no animal would have harmful parasites. Notice I said harmful.
HOWEVER, this is not a perfect world, we do not have perfect animals, and the feed is BY FAR perfect, no matter what feed you get.
That being said, yes......worms are normal and it is normal for all birds to get them.
Some people worm frequently, like every 6 months if the birds are free range, once a year if not.
I myself have never used any chemical dewormer on any of my birds, whether they need it or not. Instead, I used natural things like diatom. earth and ACV, garlic and pepper, usually for about 2 weeks.
Deworming is a personal choice. I know a lot of people that do it constantly and tax the systems of the poor birds far too much.
So, if you feel like you need to, use the least harmful of the dewormers and make sure you don't do it more than once a year and always alternate between two or three brands or methods or else the parasites will become immune.
Hope this helps!