That is not a lot of time and with plants you have to account for the fact that insects, diseases and weather can all step in and spoil the show. That said, in your southern location you have quite a bit of good growing conditions to go between now and the big day. The big issue is when will the first frost arrive. It is too early to plant cool season flowers. Warm season flowers are okay now but could be burned badly by an early frost.
Thus I would suggest you consider putting out white mums sometime in the next month. Such plants look good but the cost may add up as you fill that planting area. Another option is to plant white flowered types of the large flowered zinnias or marigolds (actually have a bit of yellow hue in the white). These many not be easy to find in local garden shops and you need transplants, not seed at this date.
Hope this helps and best wishes for the big day!
Q&A Library Searching Tips