Take your time! It takes time.
It can take a couple of years to get it as you want it.
Think about hiring tools such as a handtiller or turf cutter.
This can save a lot of hard digging and get you to some reasonable soil.
In the first year grow things you will get a return from as this will give you a boost as you are getting something back for your hardwork.
Salad vegetables, runner beans, cabbages are good examples. Try carrots and strawberries in pots while you get your ground ready.
Using weed suppressant helps to reduce the weeding.
Cover or mulch any ground you have dug or weeded until you are ready to use it.
Think about netting, fleece and covers to stop pests eating your produce. Net brassicas (cabbages, broccoli) as pigeons are partial to them.
Fleece can be used to prevent whitefly and other flying pests.
Cover what you cannot cultivate, even if it is for a year as it will help to kill off the weeds and undergrowth.
Consider covering half the plot and only attempt a dedicated section. Don't try to do it all at once.
Consider where you want your paths - you never want to be 3ft away from the middle of a bed to enable picking and weeding.
Paths can be made from weed suppressant with chippings or stones.
Look to get your shed or greenhouse in position along with any compost bins and water butts.
What size shed do you need - will it just be for tools or will you use if for shelter.
Think about what gardening tools you will need.
The basics:- Spade, Fork, Hand fork, Hand spade, Rake, Hoe, String, scissors, secateurs, gloves, first aid kit, Antihistamine (for stings).
Don't be scared to walk about the site and see how other plotholders manage their plots.