You don't need much equipment when starting.
The right clothing ensures you enjoy bushwalking in both comfort and safety. Your clothing is your first line of protection from the cold, the wind, the rain, the sun, insects, snakes and the scrub. A number of light, adjustable layers are preferable to a few layers of thick fabric. Jeans become very uncomfortable to walk in if they get wet so many people prefer to wear shorts or trousers made of light weight material.
Good footwear means comfortable light boots or runners with a sound tread. Headwear is essential to provide shade from the sun or warmth from cold winds. A waterproof jacket is also essential. Choose one long enough to sit on with a draw cord hood and NOT padded.
For day walks you need a small pack to carry your hat, waterproof jacket, water bottle (one litre), and lunch and nibbles. Consider also taking sun glasses and binoculars. If you wish to camp overnight you will personally need a good sleeping bag and backpack, whilst a tent and stove can be shared with others. These items can be borrowed or hired until you decide exactly what you need. Specialist shops and clubs can help with advice.