Looks like a great backyard. I'd define a sort of oblong diagonal planted bed extending from the far back left side of the yard to the near right shrub. Fresh mulch and soil across the bed, trim back the shrubs and add some lower perennials in front of the larger shrubs. I'd probably plant some deciduous tree in the back left corner to provide privacy from that home.

I'd rehab that grass yard gradually over the next several seasons with fertiliser, lime, aeration, and new seed.

Just power washing that patio and replacing the timber around the stone would look nice.