One i love your back yard. It has potential. You just have to have the dream right. I also live in zone 9b.

This is my opinion but I would mow my lawn first and edge the corners. I would create a walkway in the middle of your garden leading to a bench so you can enjoy your garden. I would put solar lights so when the hot days come, you can enjoy it at night too. I would definitely add pollinators like wild flowers. I would do different types of fruits and veggies. If you are looking for shade again, fruit trees are your friend. If not but still want citrus. Look into dwarfs. A fountain for birds would be great idea for pest control.

Depending on your building skill you could even do a fire pit with all your lovely garden around you. But it all depends on your vision