I don't think a retaining wall is needed. However, don't be surprised if some flat-earthers come along to insist that your earth be flat.

It does look steep enough that mulch will wash out, so I'd plan on eventually having ground cover instead. I'd also extend the bed around the corner to meet the fence. Otherwise, you'll have this strange, abandoned space there. It doesn't have to be planted, but the groundcover should be there.

I don't know what you are planning on planting there, but usually such corners are planted with larger shrubs that the rest of the bed so it is less obvious they are planted on a lower level.

I don't know if the block wall is needed but I would make the bed across the front of the house deeper. Right now, the plantings have to line up in a row, it would be more pleasing if they were staggered. I would put a few bushed in front of the new fence.

Are you saying even deeper than the mapped out plan? Currently the original bed is 4 feet deep, we plan for it to double to around 8 feet deep.

I wouldn't. It's not an area I'd want to draw attention to. The new fence is all you really need there. You can make it pretty on the street side with a nice gate. I know you have a trampoline but you won't always have a trampoline, so is there a need for that slope to be fenced in five years into the future? If not, I would avoid fencing in the slope. I might even leave the chain link fence until the trampoline days are behind you.

Raise the corner of the foundation bed so it is level with the rest of the lawn area and plant a small-medium tree or a conifer there, which grounds the house to the yard. Put in a neat row of foundation shrubs under the windows instead of hostas. Make a mixed bed along the new walkway from the porch to the lamppost. That draws the attention to the front door and the new walkway instead of to the awkward slope. Plant the bed between the sidewalk and driveway. That is enough plant material for your small home. Upgrade the lamp.

Yeah we gotta keep it fenced we have dogs.

Will the height of the new fence step down to accommodate the slope?

The only reason I would plant past the corner of the house is if you want to screen the fence. But I would want a tree somewhere between the corner of the house and the corner of the fence. And I want it level--not this:

So maybe a tier with only a tree in it would work. But I would end the first stacked wall at the corner of the house. Yes, that bed needs to be widened because you need evergreen shrubs, but not as wide as you are thinking. It's just too deep a bed for the size of your house.

If not a tier, widen the bed at the corner so it's deep enough to plant a columnar tree just in front of the front corner. Add edging plants to spill over the wall for texture and color.

You can go wild with flowering plants in the bed between the walkway and driveway, where they can be better seen and appreciated. You can even add a curved bed around the mailbox.

Understand that 'small' trees aren't usually all that small. As far as foundation plantings go, what is usually used as a small tree is really a large shrub.

I would leave it.

Celery's photo illustrates what I was describing--a bed that is only widened at the corner to accommodate a tree. Unlike this photo, your tree will partially block the window so you don't want a dense branch structure.

I like the other circular bed too in the photo but you can just continue it straight to the walkway or curve it where it joins the walkway.

When I look at the house the area that doesn't contribute to the design of house and landscape is the items behind the fence. I'd add conifers and shrubs to reduce that. You don't have to remove the stone wall for that. But you can if a less structured appearance works.

Here are some ideas: