Based on the current weather forecast, I’d say the you all are good to go on planting what ever you want except for peppers, cantaloupes and watermelons. I’d wait a few more weeks until the night temperatures are in the 60’s before you plant them.
On the flower side of things, you might wait to plant your periwinkles for a few more weeks like the peppers but otherwise I think it’s warm enough to plant what ever you want.
Here are some suggestions:
It is tough to beat Wave Petunias for filling in flower beds with their spreading growth habit.
I like Dahlias. I think you will too.