You need to give quite a lot of consideration to the location of your main vegetable plots. Many poor soil conditions can be corrected over time, but your number one priority should be how much sun the area receives – especially if you are lucky enough to be able to grow winter veggies.
You want to aim for an area that gets at least six hours sunlight each day. You should choose to position the garden so that the maximum sunlight is from the morning. You don’t mind too much if there’s some afternoon shade through summer as summers are very hot (35°C – 45°C, that’s 95°F – 114°F) and dry.