Hi @GavandKaty,
You might like to start by checking out the following articles, which will give you details on the process of planning and building a deck as well as what materials are needed and how they interact with each other.
You might also like to check out our Decking Planner, which you can use to plan out your deck and select suitable materials.
If you are planning to build your deck with a roof over the top, there is a very good chance you will require council approval, so it would be a good idea to check with your local council during the planning stage to ensure your planning is in line with their rules and regulations. Anytime roofed structures are part of the plan, there is a good chance it will have an impact on the footings required, and it is likely you would need a draftsman or engineer to draw up plans for submission to council.
Typically, a deck is built with a timber frame, with H3 framing being the timber most commonly used. The framing will sit on either posts or pedestals, depending on how you are planning to support the structure. If you are required to submit plans to council, the calibre of footings and the materials for your deck will need to be included in the plans, so it would be worthwhile speaking to your council before you start selecting materials to ensure they are in line with their regulations.
Let me know if you have any further questions, I would be more than happy to help.
Jacob
