Hi and welcome
It all depends on what you like. Petunias come in all sorts of shapes and colors and could trail over your pots and in my experience bloom like crazy. Marigolds are pretty and come in various colors.
Snapdragons are pretty!!
Go to your neighborhood gardening center and see what you like. You can also ask for help on what grows best in your area. And go from there.
There are all sorts of things you can plant. I gave you annuals which means they just put on a show until wintertime and then you'd probably have to replant the next spring. There are pretty plants that stick around for blooming time and come back each spring. Those are perennials.
Some of my favorites are gardenias and hydrangeas. But there are so much more. Those are examples of perennials.
I don't know how harsh your winters are. So some plants like gardenias and I believe hydrangeas would need to come into the warmth of your house to keep them alive for a harsh winter.
That's just my opinion and some examples 😀
Happy Gardening!!!
😀
Mindi