We have an allotment. Getting the older, neglected patch is common since one of the main reasons a plot becomes available at all is because the owner fails to tend it and they have it taken off them. It's not a massive issue IMO. Depending on the rules of the allotment you may be able to use a pathclear type weedkiller on it which will nuke it, and then a few weeks later you can clear it and dig it over. Digging over is hard work and you should do it in sections over a period of time depending on your fitness/enthusiasm.
Whilst you're digging over, get some free horse manure from a stable and dig that in to improve it. Depending on the time of year you do this, you should be able to grow at least something on it relatively quickly.
My main concern about the plot you mention is the lack of water. I don't know how you'd get around that. In the summer our allotment needs watering every day and I was doing about 20 buckets each time from the tap. No water butt is going to last long with that kind of usage. but the old hands will know what is possible. In fact that is your best bet - go down and chat to them. They know what the problems are, what the soil is like, what grows, what doesn't etc. See if they are a happy bunch.
Don't underestimate the commitment though. it's a lot of work. if you don't like gardening as an activity, the lure of home grown veg is likely to wear off pretty soon and then it's going to be a grind.
Whilst you're digging over, get some free horse manure from a stable and dig that in to improve it. Depending on the time of year you do this, you should be able to grow at least something on it relatively quickly.
My main concern about the plot you mention is the lack of water. I don't know how you'd get around that. In the summer our allotment needs watering every day and I was doing about 20 buckets each time from the tap. No water butt is going to last long with that kind of usage. but the old hands will know what is possible. In fact that is your best bet - go down and chat to them. They know what the problems are, what the soil is like, what grows, what doesn't etc. See if they are a happy bunch.
Don't underestimate the commitment though. it's a lot of work. if you don't like gardening as an activity, the lure of home grown veg is likely to wear off pretty soon and then it's going to be a grind.