Starting with the all important footwear, let’s say straight off that tender skin and new boots are not likely to get you through the hike without experiencing some pain caused by blistering and chaffing.
Boots are generally considered to be superior to sport type shoes due to their height and stiffness which provide ankle support, and their sole rigidity which prevents foot bruising and promotes confidence when walking over difficult terrain.
Cheaper boots, generally of a woven fabric, are softer and kinder to the unseasoned foot but they won’t last or support as well as the more expensive heavier leather boot that often takes many km of wear over a lengthy period to make a heavenly marriage twixt foot and boot. Walking in sodden boots can speed the process up.
When choosing new boots, complete with comforting inner sole, wear a thick spongy hiking sock and ensure that an easy finger thick gap exists at your heel. This will allow the foot to be kept back in the boot by firm lower lacing, thus preventing the toes from being forced most uncomfortably against the toe of the boot when descending steep slopes.
Moving up, seed-guards or gaiters keep the annoying prickles out of socks. Short pants provide cool freedom but allow bush scratching and give less protection against sunburn and the occasional tick than lightweight longs covered by the gaiters. You may consider spraying your legs against tick bits, particularly if you are heading into long grass frequented by cattle.
Ideal top clothing is a preferably white and lightweight lounge type shirt without the heavy floppy cuffs. With its high collar and long sleeves sunburn is held at bay. Cream the back of your hands though.
Find a hat that’s not too rigid and hard but that is able to support a useful brim to keep the sun off the face in particular. The popular baseball type cap does not help much when the sun is on the side.
Now on to the bag that is to carry your requirements. Small day packs do not quite accommodate what really should be carried, namely: rain/wind jacket, light long sleeved jersey, lightweight warming jacket in the cooler months, swimming costume in summer, basic first aid kit, toilet paper, lunch box and optional tea kit and stove, and up to 2 litres of water either in the side pockets or carried separately on a shoulder strap or in a waist belt. A quantity of raisins or the like easily accessed in your ‘mouchie’ bag will help to keep up your energy level.
Getting back to the size of your pack. For day hikes consider a 35 lt model with usefully sized side and flap pockets and a net wet cosy container. Use a plastic bag as a liner to keep things dry.
Do not stay home if you have a bad back which just can’t carry this lot on the shoulders and waist band. Waist level bags that will carry most of the above are available from one of those interesting camping/hiking equipment shops.