Depends on the size of your coop and run area really. The "standard" seems to be 4 square feed per bird inside, and 10 square feet outside of run area. Let that the be the deciding factor on how many you get. Since it is an hour away, I would call them and see if you can pay for some over the phone to save them. I believe there is a 6 chick min in the state of Indiana. I also believe they sell the chicks as straight run, I would ask them if its straight run or pullets. With straight run there is a 50/50 shot (or better) of getting cute little boy chicks. Do you live in the city, or can you have roosters where you are? Also, you will need a brooder box, bedding, heat lamp, food and waterer, chick starter.
Find out how old they are, in my area they appeared to me to be a week +. They should be able to tell you when they got them in. Then set the brooder up. They will need to be fully feathered out before they go outside. Depending on breed, that can be up to 7-8 weeks of age. Which they will need to be inside. Its not impossible to get chicks this time of year, just takes a little more doing to get them ready to go outside as it will be colder.
If you ever have any question, just ask. The people on BYC, and this thread in particular, are so friendly and helpful. Lots of experience people here who are will to teach. And this thread runs so fast, if you are gone for a couple of days, you may have 25 pages to read. It can get crazy.
Best of luck to you and your chicks,
Deb