Meet with a local landscape designer so you can have a good landscape and hardscape plan for your lot. If you go to a local nursery, not a big box store, you will get the help you need and they can recommend a good landscape designer. It isn't a matter of just sticking random plants into the ground.

@Denita(Zone 10) thanks for the advice. I do plan to work with a local landscaper.

Before you made your design, did you consider your goals for the space? How will you want to use the yard? sunny or shady sitting area? play area for kids, whether a climbing area or sand box or swingset? an outdoor cooking area? a sports area such as croquet, badminton, or basketball? Veggie garden? flowers for cutting or outdoor decoration? paths, walkways, and access to various areas, etc . . .

What views you want to block or enhance that aren't on your lot? Whether it's the neighbor's trampoline or gorgeous pine tree or a utility pole, there are often sights that you may want to hide or borrow from the surrounding area to make what you see nicer.

Think about the views seen from inside the house and from the car as you come and go. Especially in winter (and at least in the part of OH where I grew up, winter was often dreary!) the views you can see from windows where family members most frequently look out can make life more interesting. Place evergreens and plants with colored twigs or interesting shapes where they can be seen from inside for winter views, and plan some plants for warm weather interest there also. Think about near views from windows for critter visitors, whether bird feeders, plants for hummingbirds, perches for flycatchers, a bird bath, etc. if that is of interest to you.

Have you mapped out where shade currently falls in the yard and where you might want it?

Do you need outdoor storage of any kind, whether for the trash cans or the lawn mower or for outdoor tools or sports equipment?

How does water move off the impermeable surfaces such as the driveway or roof? Have you accounted for that in placing beds, etc. so that you don't impede water flow?

Placement of flower beds and other plants should be deep enough front to back to be proportional to the house and in spots that complement the architecture.

Is your front walk wide enough for two people to walk abreast or is it the typical narrow walk?

Do you like yard work, or would your prefer to spend your time in other ways?

So before you start planning, you should have answers to these questions and considerations and probably a lot more that haven't occurred to me offhand.

Right now we don't know what the house looks like or if the dark gray areas on the plan are all impermeable paving or perhaps some permeable hard surfaces such as gravel or anything about how you want to use your yard or whether you even like yard work or would prefer to hire a mow, blow, and go service or how water moves off the roof and around the property. So it's really difficult to provide much feedback with such limited information.

If you want to do this on your own, I would most likely get some books on landscape design from the public library and look through them for what else you might need to consider. Visit whatever arboretums, botanic gardens, zoos or well designed parks are in your area to see various plants at various times of year to get some idea of what plants do well in your area beyond what you might see in an average nursery. (As a kid, I learned a lot from the Holden Arboretum and the plantings at a couple of zoos and cemeteries.)

Perhaps as Denita suggested, get some input from a local designer.

When you have more information, if you want more input, add photos of the house and information of how you want to use the yard and it may be easier to give feedback.

@NHBabs(4b-5aNH) thanks for the thoughtful reply. You brought up a lot of good things I need to consider. I do plan on getting a local designer involved at some point. I was more or less just trying to get a basic, high-level idea of what I wanted. Thanks again!

Actually, you want to start with a landscape designer rather than bring them in down the road :-) A skilled designer will be able to better elicit from you via in person discussions and a site visit what you want from your garden and how best to use it. They will help you formulate that "basic, high level idea" and then condense and synthesize it to fit your property and your needs. That's what they do :-))