Chicks shouldn't need worming unless you see worms in the poop. Hard on their little bodies.
My flock was about 10 months old when I wormed them the first time and I do it yearly now. Some folks never worm, but I figure if my dogs can pick up worms just by going outside, so too can the chickens.
I used valbazen, which is a cattle/goat wormer. You use it "off-label" as you do with just about any chicken wormer, since about the only one readily available for chickens, wazine, only gets roundworms. I came across an ad from a guy in Alabama selling broad spectrum wormer for chickens. Turns out it was valbazen, just put in really small bottles with a really big price.
Valbazen is a broad spectrum wormer. You give 1/2 cc orally, undiluted for standard sized birds; 1/4 cc. for bantams. You can do a search for eprinex and ivermectin; both also cattle wormers that are also used for chickens.