I live in west central Indiana and we receive 44 inches of rain annually. Even with 44 inches annually, our soil gets pretty dry in late July and August, and we do supplement with some sprinklers every few days as needed. 5000 square feet is approx 70 feet x 70 feet or 0.12 acres - about the size of our vegetable garden I think
I am a reluctant gardener - never really liked it as a chlld and still don't - but my wife grew up on a farm, and expects farm fresh corn, tomatoes, beans, black berries and water melon. By farm fresh sweet corn, I mean less than 4 hours from the stalk in the field to our dinner table. So I have learned a little about gardening along the way. A Troy Built Pony or Horse tiller is quite helpful to break sod and prepare the soil for a garden. We added several tons of horse manure a few years ago, to help convert the low grade clay soil we had, to nice black loam presently. I try to collect the oak and maple leaves in our yard each fall and let them decompose over the winter on the garden soil before tilling them in in the spring.
My spouse is tireless and relentless in creating beautiful gardens of both flowers all around our house and barn, and a vegetable garden with sweet corn, beans, water melons, black berries, and tomatoes. (If our tomatoes don't weigh at least a pound each, she's not interested in them - we eat tomato sandwiches almost daily from late July to mid-October if we're lucky.)
Good gardens take some time - my spouse has been at it for many years and in additon to vegetables we have lots of plants for hummingbirds and butterflies - butterfly bush, butterfly weed, milk weed, bamboo grass, irises, and many others that I don't remember the names of.
With only 15 inches of rain a year, I think you will have a significant challenge for a large garden, and will need to suplement your water in some manner. Nice link here about desert gardening in the South West which look quite lovely - https://www.bhg.com/gardening/gardening-by-region/desert-southwest/?page=2
Here's one about southern Nevada - that sounds like a tough place to garden to me - https://www.unce.unr.edu/publications/files/ho/2001/sp0115.pdf
Here is a swallowtail on a butterfly bush in our garden
Hopefull we will get some more knowledgeable garden folks here to help you with your question