For a weekend getaway, pack one or two changes of comfortable clothes, and think layers. For tops, a couple of T-shirts or tank tops, a long-sleeve T-shirt, flannel shirt, pullover sweater, fleece jacket, and waterproof jacket should prepare you for most conditions. For bottoms, bring shorts and pants (one or two pairs of each) and long johns or leggings for warmth or to sleep in. Remember to include enough underwear, as well as a bathing suit, a knit hat, a billed or brimmed hat, sunglasses, and gloves.
Be good to your feet: Bring extra socks and at least two pairs of shoes (especially if you're camping near water or if rain is in the forecast). Unless you're backpacking or doing serious day-hiking, hiking boots aren't necessary. If you're backpacking, they're a must, and they should fit well and be broken in before you venture far in them.
List the toiletries you'll need. The basics are hand soap and a towel, toothpaste and toothbrush, sunscreen, bug spray, and lip balm. Lotion, toilet paper, sanitary products, and prescription medications may also be of use. A basic first-aid kit contains adhesive bandages, tweezers, antihistamines, aspirin or ibuprofen, and antibacterial ointment. If you're hiking, add moleskin (for blisters) and a sports bandage or two (for joint support).