Can you add a photo take from across the street that shows the entire width of the property?

If it were mine, I would make both beds the same depth, the distance between the house and the sidewalk. I'd also widen and center the walkway - I know it looks new, but it's too narrow for comfortable walking for two people, and the off-center on the step is a bit odd. I'd leave the right side where it is and make the walk wider on the side toward the house so that it is centered on the step. If you can't do that, I can make a couple of suggestions to mitigate the off-center walk, but widening it would be preferable.

It looks like what is currently planted in the beds is too close to the house. I plant so that there is at least two feet between the house and the edge of the plantings so I can easily get in to do maintenance and so the the plants aren't brushing against the house. It also means that the plants aren't under the eaves which are either bone dry due to the rain shadow from the eaves or getting dripped on by whatever comes off the roof (though in your case it looks like you have gutters.) If you want, you could plant some kind of dry-tolerant groundcover such as pachysandra back there to reduce weeds and prevent splash back of soil onto the house.

I would put evergreen shrubs of some type at the back so you have something of interest during the long season when deciduous plants are bare. Then I would plant the deciduous flowering plants in front of that. I would put plants that get a bit taller (but will still be shorter than the roofline) in areas where there aren't windows and restrict the plants in front of the windows to ones that stay below the level of the windows so you aren't having to constantly prune.

I'd start by removing what is there, either trashing it (barberries are invasive in many parts of the US) or putting on the curb/Craig's list with a free sign or for the plants you want to keep, repotting them until the bed is prepped (heavy duty trash bags work well). If nothing else, I'd keep the Hydrangea and put it in the sunniest available spot, but farther out from the house since it can get to 15 ft wide without pruning, so you should give it at least 6' from the house if you plan to prune it. The azalea, rhodo, magnolia, and lilacs are all good plants, but the magnolia and lilac like more sun than is probably available here and will also get too large. Do you have a spot in the back yard or side yard for them?

Before replanting, have a soil test done so you know your pH and if there are nutrients missing. You can also do alow-tech soil texture test to get a feel for what your soil texture is like (though I don't bother with the drying and sieving, just shake it for longer.) Regardless, I'd also add a goodly amount of compost since in most cases, the soil near the foundation tends to be in relatively poor shape and compost will improve nutrients and texture regardless of what the issues are. If turning in compost in an area that large is too much for you, hire a couple of high school students to do it for you. Having good soil will be key to a successful garden.

If you haven't done a study of the amount of sun (does it get any direct sun or only what's filtered through the trees?) do that, checking every hour or so over a whole day while you are home. Things will be different in high summer so if you have photos from earlier in the year check them as well.

Once you have the bed prepped you can plant, starting with the shrubs and then adding the perennials. If you are in New England, I can make plant suggestions, but if you are in the midwest, your soil texture and pH may be too different from mine for me to make suggestions.

MANY thanks! Your suggestions are very helpful! You're correct about the narrow sidewalk and asymetrical stoop; changing them is not in the budget, so hopefully nice landscaping will optimize this area for now. We are in zone 5/midwest, so the area has dapled shade with hot summers.

OK, then my suggestions would be to either:

get a matching pair of large urns. Put one on the left side of the stoop and put the other on a pedestal that is off the right side of the stoop. That way the urns will be the same distance from the door framing it and add some balance.

OR

Get one large urn, fill it full and embrace the asymmetry by placing it on the left.

Use a photo of your home and find a photo of a large urn you like and try it out both ways visually to decide which appeals to you more. It may depend on how you plant the garden which strategy looks better. Regardless, don't undersize the planter.

I tend to plan along the lines of generalities first: a 6' evergreen here, a 3' broadleafed evergreen there, a gold-leafed deciduous shrub . . . etc. There are regional forums here, so once you have done your general layout as far as type, number and colors of plants you want, you can ask there or in the perennial or shrub or conifer forums or in the regional forum that's closest to you (such as Great Lakes, Mid-west, or WI, though I don't know how active they will be) as well as here.

Thank you!