Allotments - especially in the first two years - are pretty hard work. Until you have decided on a permanent layout and got rid of the perennial weeds.
I got mine 7 years ago, it is only me and my lottie neighbour that are still there on our allotment site, every single other person that got one since then has packed it in. There are a few old chaps who have had one for decades that keep them, but they spray everything in sight and are there all day every day.
My top tip if you are going to go for it [and the worst that can happen is that they kick you off if it is too much] are:
Clear a bit, cover it with a mulch or plant it straight up. If you leave it, weeds will germinate and you will be back to square 1. By clearing, I mean dig as thoroughly as you can a square meter at a time, remove ALL weed roots and any debris [you would be surprised how much rubbish is in allotment soil - glass, plastic, metal etc]. Then cover with a mulch such as cardboard, straw, grass clippings, newspaper, shredded paper - anything that stops the light but lets water through and will rot down eventually to make better soil.
If you have no water, collect some from the start using anything you can.
If the allotment is in a bad way, mow or strim the whole lot down, and cover with cardboard, weed fabric, a tarp - anything to kill the light and stop the weeds from growing, as you get around to clearing section by section [see first point].
Decide at the start whether you are going for a bed style or row style. I always get grief for having beds not rows as people say that the paths are wasted space. However that is not true. the benefits of paths are that you never have to weed that section, or dig it, as it gets firmer over time and you don't walk on the beds, whereas if you do the traditional rows, you are creating mini paths every year that all need redigging each time you put a new crop in. Also - look at the attachment and you will see that you can get 3 times as many plants in a block pattern in a bed than you can in a traditional row. It is better for the soil, as you only need to dig out/hoe off weeds that grow on the beds, and because you haven't been walking on them it is much easier to get those out. And people don't inadvertently walk all over your newly planted or sown beds.
Compost everything organic, except the roots of perennial weeds and any weed seed heads. You can have a traditional compost bin separate from the growing space, or what I do is to have a few Dalek compost bins around the site, sat on beds, so that the compost sits on the soil and just needs to be raked over when you turn the compost, rather than barrowed back and forth to a separate compost area. It saves hours of backbreaking shovelling and barrowing.
If for the first year you cannot possibly deep dig and clear the whole allotment - start at one end and work down after strimming and covering the rest then, around the end of June time, pop around 10-15 pot grown pumpkin/squash plants into the non deep dug areas, spaced out equally [uncover the mulch, dig a hole, put the plant in, firm up with soil, water in and put the mulch back around the sides leaving the stem and leaves sticking up]. These will grow over the mulch, and make it look as if the whole plot is being used in the first year, even though you have not dug it over. You can also do this with runner beans, just pop some plants in through the mulch, stick some bean sticks or canes in, and let them grow up. Also, you can do this with sweetcorn, but grow these in a block with about 12 inches between each one. This will give you another winter to carry on digging out all the perennial weeds and avoid the 'letter from the council/allotment people' telling you to use the space fully.