new allotment

I have just taken over a 10 rod allotment that has not been used for at least a year.  The earth is thick with bindweed and couch grass.
Where do I start ? 
Please give me advice   

Axel2801

There is some excellent advice on this very site:

Clearing a New Allotment or Vegetable Plot

I only tell people what I would do in that situation when we took on more allotments that hadn't been cultivated for a couple of years we had couch grass bindweed and others we took over the allotments in October of that year all we did was tidy up remove all the old rubbish that had been left
 had a load of manure delivered to use  half one year and to save the other half for next year

then come spring we sprayed the allotment with roundup only once mind then after three weeks we ploughed the ground and then cultivated it we set half of it with potatoes the other half we grew brassicas and othere veg with a good helping of cattle manure we had good results but on hindsight we should have done a soil test but hay hoe that came later and  all be it the lack of  sulphur was flagged up in the test

anyway that's what we done and it saved us a lot of time and hard work  but everyone to there own good luck with your new allotment what ever you decide