The first thing you need for a 7-day backpacking trip is a backpack. A good backpack will last you a lifetime, but it also needs to be comfortable. Also, include in your checklist: 1. A backpack. 2. A sleeping bag. 3. A tent, hammock, tarp, or another shelter of your choice. 4. A stove and fuel to cook with (or a camp stove). 5. Clothes and shoes appropriate for the weather (and a change of clothes just in case). 6. Food and water for your trip, plus all the supplies you'll need to cook it (e.g., cooking pots, dishes). 7. A first aid kit and some other items that might be useful on an extended trek like hiking boots or gloves, sunscreen, toilet paper, etc... 8. good pair of boots