Avoid the trap of the Damas/ Ficus tree!
Grow a few bouganvillas, they clearly thrive and love this climate.
Try to grow a papaya plant from seed (get fruit from supermarket, set aside seeds, dry out in sun and plant). They look nice in pots until they get so big that you need to plant them in soil.
Just remember to either plant things in the shade or get shade cloth (green mesh netting) to roughly cover areas that get direct sunlight.
Rocket seeds (from a packet) grow incredibly fast (great to introduce kids to gardening) and ready to add to your salads within a few weeks.
I've had recent success with sunflower seeds and eggplant seeds, carrot seeds (all of these were Alta Lunghi seed packets), okra seeds (from some organic okra bought from Union Co-op so quite cheap).
Another fun thing to plant are whole onions (esp those already starting to sprout so quite useless for cooking!), individual garlic cloves, a knob of ginger. You can get some great-tasting green shoots that really add to finished, cooked dish. The onion greens are a great sub for spring onions, the garlic shoots for chives, the ginger shoots for lemongrass (ok I think someone may come along and yell at me for typing that, but I've done it and no-one was the wiser).