A wet spell while I was away means that the weeds - and especially the nettles - have returned with interest. However, the black plastic mulch has stayed in place - at least under there the weeds won't be getting any worse.
Over the last couple of weeks I've bagged up rubbish and managed to clear three patches of actual earth, each about a square metre, that I hope to make into small raised beds. The earth, once the grass and clover have been scraped off, is fairly loamy with lots of stones and lumps of chalk, but very compacted and needs a lot of organic material digging in. It doesn't seem to drain that well - I dug a small hole and poured in water which sat there for some time - but hopefully making raised beds will improve that. I'm about to order a compost heap frame and raised bed kits. The allotment DIY ethos says you should make these yourself out of pallets that you magically find lying about - but my time-poor ethos says it's easier to buy this sort of thing than struggle with tasks for which you have no aptitude.