For short and simple trails, you don’t need much with you. Bring plenty of water (a good baseline estimation is 0.5L of water for every hour of walking), some snacks and a small first aid kit in a backpack. Other items you might consider are sunglasses, insect repellent, a portable phone charger and something warm to wear (just in case you’re out longer than planned).
Avoid wearing cotton clothing as they retain moisture (from rain or sweat). Instead, try moisture-wicking fabrics like polyester or wool. Cover up as much as possible and use plenty of sunscreen on any exposed skin. You can also wear a brimmed hat or cap to protect yourself from sunburn.
For footwear, a pair of sturdy, comfortable shoes will be fine for easier trails – although it may be worth investing in a solid pair of full or mid-cut hiking boots if you plan on tackling harder routes or regular bushwalks.