Raising chicks can be complicated, but not nearly as complicated as some beginner resources would have you believe. Many things that people like to give their chicks simply aren't required. Some things that people suggest aren't really recommended. They don't need vinegar. They don't need electrolytes. They don't need treats. They don't need grit. They shouldn't be on small pine shavings—and I'm sorry, but there are small pine shavings in all the pine shavings I've seen available, so I don't use them myself.
Just a note about purchasing chicks. If you buy straight-run chicks, the odds are that you will get 50% males and 50% females. Sexing chicks is a complicated issue and the only 100% reliable methods are dependent upon the breed. For example, most sex-linked chicks are reliably sorted by color. If you don't want to deal with roosters, don't buy straight-run chicks. Even with vent-sexed chicks you can get some males, so be prepared to live with them, give them away, or kill them. Whatever you do, don't start killing chicks based on some ridiculous method like holding them by the neck to see how much they struggle.
8 Day Old Chicks in an Outdoor Brooder Room (Posted 4/14/19 KAO)
Assuming you purchase chicks from a reputable company like Cackle Hatchery, you will receive chicks that are from 1 to 3 days old depending on how far you are from the hatchery. Please be prepared to pick up your chicks as soon as the post office calls you and have their new home ready for them. Follow the care instructions from the place where you get your chicks. Here is what the instructions should say:
Updated: 4/1/20 KAO
Using Vinegar to Prevent Pasty Butt (Linked 4/30/19)
Vent Sexing Day Old Chicks (Linked 4/14/19)