Take back the backpack, chickens aren't that type of pet.
Chickens need to stay in their area, your yard/coop so they don't catch disease, they also stress out with new environments and new things. Constantly putting them in a new environment will ruin their mental and physical health.
You want to look for active, perky chicks, the feed store can't sex them but they likely have batches of sexed (with 90% accuracy) chicks or sex linked chicks. (Comets, stars, red, gold, blue, black sex links etc)
Bantams typically aren't sexed, they're too small to do it without hurting them.
With the money returned from the back pack, you want to get some grower feed, a heat lamp, small feeder and waterer and a bedding material. most places have big bales of pine shaving, I use pee pads.
Not cedar shavings.
They don't need toys or those mini perches or treats. colored ping pong balls, a hand mirror from the dollar store make good toys
They're too little for treats until about 3-4 weeks old, then you want to give them a little chick grit before and during. Pieces of fruit and vegetables are good treats. A good treat is to add warm water to their feed in a small dish so its like thick oatmeal, they'll go nuts. Make sure the pieces of fruit are big enough do they don't swallow them.
Your brooder can be a large cardboard box, a stock tank, or a large storage tub.
You want the heat pointing to one end so they can cool off and warm up if needed.
I'd cut out one side of the brooder and replace it with something they can see through, like hardware mesh, screen, plexiglass, plastic, etc and have the brooder up on a table so they can see you coming and don't suddenly appear over head.
Since it's warmer, you can move them out to the coop in about 2 weeks and keep the heat with them until 4 weeks.
You can hand feed them, or just leave your hand there so the get used to it.
You can say the same thing every time you feed them or treat them (i.e hey girls, time to eat, here's some treats!)
Don't let them ride on your shoulders.
just sit with them quietly.
You can let them outside for trips when it's warm, with supervision.
Good luck!