The beds along the sides of the yard (between walk and fence) and the walks themselves both look far too narrow. Are the walks pavers or poured concrete? If they are pavers, you could take them up and rearrange them into a patio outside the back door (instead of a deck). Expand the side beds to at least 5-6' deep. Then take up the mulch from the part of the yard beyond the tree and plant grass instead. Is that a poured concrete slab in the back? Do you want to keep that?