Welcome to the Bunnings Workshop community @Brownie2. It's sensational to have you join us, and many thanks for your question about building wooden chairs.
Since outdoor chairs come in various styles and degrees of construction difficulty, you might like to start by letting us know what type of tools you have available and your level of skillset. Our members will then be better informed and able to offer helpful suggestions. Also, if you've seen any chairs that have inspired you, please let us know.
Using recycled pallets to create a rustic, industrial-style chair can be an effective way to create seating, especially for a beginner to D.I.Y.. Simply stack the pallets on top of each other and secure them with nails or screws. You can add cushions or pillows for comfort. Pallets are typically available at most of our stores.
Swing chairs can be built with a simple frame using sturdy timber and wooden slats for the seat. The chair can then be hung from chains or ropes. Here's a great example from @LePallet with his Outdoor daybed swing.