It is quite late in the season to start planting. Grow some stuff if you can - quick growing salads, etc., but I would concentrate on getting it clear for next year.
If it is overgrown, kill what you can using using weedkiller - I try to avoid chemicals on my plot, but it will save loads of future work.
Bonfires are good if you are allowed - They kill the weeds and leave high potash feed for next years plants.