What about putting in a raised veggie garden, raised because it's easier on your back, and also some fruit trees.
Alot of the plants you put in will depend on how much watering you want to do and how much water you have.
There are many natives that flower for many months and will attract birds.
Find a nursery near you and pick their brains. Also go for walks in established areas near you and see what has worked for them. Be brazen when you find them in the garden and ask what works for them and what didn't. You may get alot of cuttings which will save you alot of money.