It's been one heck of a year for weeds here with all the heat and more than regular rainfall.
I know, it's a depressing sight to realize how all the previous year's effort is quickly overrun in such a short time.
Rather than tilling, which will probably create a problem with fall rains washing the soil out, you might want to have it mowed low, limed and oversown with good grass seed.
Anything floral you want to salvage can be potted up (weeds removed) to do something or nothing with.