Smother it as best you can with mulch if you have it. Like Matu said, cardboard works very well with some straw or chips on top. You could also chop it low and then run
chickens on it, if you have them.
In my garden I mulch like hell. Any weeds that make it through are pulled or chopped and fed to pigs or
chickens. At the end of the season I let the
chickens at it to finish the cleanup.
If it's too much to keep up with all of it, focus of the most productive areas and then come back to the tough spots later. It's frustrating for the first few years, but it'll come along. Persistence (and chickens)
Best wishes