First of all - you need to practice the skills you'll need before you get to the backside of beyond, or you'll either kill yourselves, injure yourselves, need rescuing, or have a lousy time.
Go to the local Boy Scouts office, and look for the merit badge books on backpacking, camping, wilderness survival, etc. They are usually about $2.50-3.00 each, and are good condensed guides to the topic. Study them. Pass them around your group, so the others can study them, too. While at the BSA store, ask for their recommendations on local camping and outdoor stores, and go there to find equipment.
For cooking, I recommend a small gas backpacking stove like one listed in the first link below. I have one that uses screw-on cartridges of a mix of propane and butane and pentane, I think, but there are others. Mine is small, powerful, easy, and I have used it for cooking for 2 for a week, using less than 2 small cans of fuel.
For water, you'll need either guaranteed pure water sources, or a water filter, or some other way to purify water. I recommend you have at least 2 ways to do this. Filters are available at many outdoor stores. You may want to look at the iodine tablet methods as well. Just be sure to study them and how they are used, and practice ahead of time.
Food - if you have to carry your food in, look for light stuff that can be mixed with water. Lots of backpacking stores carry dehydrated foods, but these can get expensive if you try to buy a week's worth of food this way. You might ask the Boy Scouts again for the name of some of the backpacking merit badge counselors in your area, and get an overview of the process.
Assemble your other gear - tent, sleeping bag, cooking gear, etc, and go out camping to practice these skills. Otherwise, you will NOT enjoy your first time out in the woods.
