Hannah Barnum wrote:
I am planning to be married in my garden this fall, likely october 11. I'd
love suggestions for plants that will have something to show at that time
(fruits, flowers, foliage?) - especially fast-growing vines to
cover/decorate the falling-down barns . . . any wildflowers? Most of the
space is full sun.

By that time, you could have some impressive displays from a combination
of hyacinth beans and moonflowers. The moonflowers would only be at their
best in the evening, of course.
Both are fast-growing annual vines with potential to grow ten feet (at
least) up to maybe 20 feet under good conditions. Both are twiners, so
they'd need some strings or other support to grow on.