One of the joys of walking or hiking is that these activities do not require a lot of money. If you are just beginning, do not spend your hard-earned cash until you decide that you wish to continue. However, if you decide to purchase hiking gear, remember that costly items can be a good investment. Quality gear will work well, prove durable, and be a pleasure to use. A cheaper item will often fail under stress.
On a full day hike you will want a lightweight day pack with padded straps. In hot weather a belt pack or fanny pack can be more comfortable because it allows your back to breathe and also avoids the problem of a stiff neck and sore shoulders. A couple could get all their necessary gear into one day pack and one fanny pack.
Each item of equipment that you carry in your pack should be as light and as small as possible. When hiking or backpacking, "pleasure is inversely proportional to the weight carried". In other words, less weight will mean more fun. Carry a small first aid kit in a plastic pouch; essentials are moleskin or molefoam for padding blisters as soon as you feel a hot spot on your foot, a small pair of scissors, and an elastic bandage for sprains or sore joints. From May to August, use insect repellent - probably the most reliable is that with a high concentration of DEET. Pack a small flashlight with long-life batteries: it is so light that you will forget it is there until you need it. A Swiss Army knife is the most versatile tool you can carry. Spare boot laces have many uses, including repairing a broken pack. A good whistle will help get attention in an emergency.
In hot weather, you will need a lot of water. Wide-mouthed screw-top litre-sized bottles are ideal: if you freeze them the night before you hike (leaving room at the top for expansion) and carry them wrapped in a towel or sock (to absorb condensation) you can have cold water on the hottest day.
Store your hiking gear in your pack - that way you will not forget it when you go hiking. And use your ingenuity - adapt everyday items for hiking and increase your fun on the trail.