How to improve yard on a budget

Hi everyone. I've tried using some remodel apps, but they don't really understand what's in the picture. I'm trying to improve this yard on a budget. Do you have any recommendations on what I can do or an app that might actually be good. I was thinking about starting to paint the 2 walls with some granit spray, but then what? I want to make it to stand out a little bit, but on a budget.

I'm grateful for any recommendation.