Powerwash and add large, colorful pots of flowers of varying heights and a bistro table and chairs. Are you allowed to hang something on the fence?

For the patio, after you clean everything, I think potted plants and some sort of chair/table would look nice. On the divider, maybe a potted vine and trellis? I’m not clear on what part of the yard area is yours, so I just put a shrub in the corner.

My app choices are limited, so not necessarily these exact colors/styles/setup, but just to give a general idea —

This, but with adding some seating, too —

ETA: Didn’t see Sammie’s post before ... thinking along the same lines. :)

What Sammie said and I'd put an outdoor love seat or two small sitting chairs too. how much grassed area is yours? You could border the grassed area with boxwood or something like bourganvilla if your climate allows. Then choose if you want a small patch of lawn or more patio out of gravels, stones mulches etc. which can be very decorative and nicely low maintenance. Didn't see the above also before hitting post..same ideas would just utilize the space to the left where the larger planter is placed for a second chair, I would put two chairs and a table closer to that area, just because it looks like it may fir..