I agree with lefty. Really think you should cut back the area. Even if you don't pave in the degraded area just plant it will look larger. Two levels shrink the space one level feels more like a room. Also I can tell the fence is your neighbors because the rails are facing your side. I would face the fence so that it looks better in your side.

You have several choices at different price points. 1- Sheet rock, plaster and paint This is the most expensive option and will add the most permanent value to your home. 2-Wallpaper over a heavy liner paper. 3-Prime then paint the wood, it will give you a stripe effect. Let me know what you decide to do. Linda

Where is your house? Low maintenance plants depend on the zone. I wouldn't plant in your rock skirt. Ideally you'd put your rock skirt around the house and then planting beds outside of that. The skirt keeps mud and dirt off the house and let's you spray for bugs etc. since your skirt runs right up to the driveway on that side, I think your options for plants would be some large pots or window boxes. I'd paint your foundation the same color as your grout in the brick to help it blend in.

We solve this issue with our clients all of the time with outdoor water features. We recommend getting a water wall that is suitable for both indoor and outdoor use. Not only will they drown out the noise but will also act as a nice privacy wall. https://www.soothingwalls.com/outdoor-fountains/glass-outdoor-fountains.html