Prepping the soil is key to a flourishing garden. Using Miracle Grow around plants is a good starter, because every fall it will get tilled into the soil until next spring when more MG is placed around new plants. A continuous cycle leading to a black soil garden in a few years. I save egg shells which is pure calcium rinsing them out to dry in a bag hanging on the back porch. Crunch them up in the bag spreading on the dirt. Harvesting sweet potatoes I see roots attached to pieces of shell. I do my own hair cut saving the hair to spread over the garden. If not using self lighting charcoal then add the ashes from your Weber to the dirt. Every year I use a lawn sweeper behind my golf cart to collect leaves to burn them over the garden. Any leaves not burnt get tilled in.
Y'all out there in AZ should try a container garden. Plants need the morning sun especially tomatoes after that reflected light is just fine. Is there a spot next to the house that has a bit of shade during the day? Containers on wheels makes it easier to move around and to keep the pot off the cement. I have a tree which shades the entire garden from the afternoon sun here on the east coast of NC. Only 100° here in July-August with 100% humidity feels like 116 especially with taking medicines so I know about heat.2¢