How sunny is that spot? That will determine what you can plant. Looks like there is a tree that provides shade.
Personally, I would plant a tight clump of daffys in the upper left section of that bed. Then you could easily plant some summer flowering annuals in the rest of the bed.
The azalea will grow but give it some time. I doubt it will fill in all the way across.

That's a decent number of daffodils for that spot even if you could add more. Daffodils will usually naturalize an area also, so you don't necessarily want to fill it up already, even though we want to have that full look asap. At the same time, naturalizing isn't something that will happen quickly, so it's up to you how you may want to fill it in.

Other perennials that I like to plant with my daffodils:
freesia, Oriental lilies, rain lilies. Of course, do them in some arrangement of where they are planted to give some pleasing arrangement.

My yard faces north so pretty much for the rest of the afternoon, they are in shade. Columbine flowers do well in that spot.

While these perennials are your repeating plants, you may still like to add annuals also to the same bed. You'll have to add those every year unless they reseed for you.

Azaleas may not grow very fast to fill in a spot, depending on growing conditions, but if you're going to get more, see if you like the reblooming type also (they bloom several times a year)

How about some azaleas along the border of the path to the house. Also do not plant anything close to the house because it will grow eventually and be too close.