Where is this garden? That will help folks know what is native.
Penny, it would also help to know the available sunlight. True "native" plants are those that were growing in the United States prior to our early settlers. Some gardeners use the term"native" to refer to plants grown in that specific time period in the area in which the garden is being developed whils others will accept those from other areas in the United States .
Where are you located> What are the light, moisture, soil, temperature conditions? What zone are you in? There are so many wonderful plants to select from.
Penny, you will get lots of ideas once we know where you garden.
Also, beware of carefree creepers, they may take over.
I use Creeping Jenny in many places i want a bit of colour and you can let it grow to any length you want, the light green is a beautiful contrast to any dark colours in the garden