It always seems a bit dauting so do it bit by bit, on specific areas as opposed to trying the whole thing.
I would decide which areas you wanted to do first, and if you can cover the others with tarpaulin or weed membrane and leave them be. Roll those areas back when you are ready to tackle them.
For the areas you tackle, as mentioned above no dig is the least back breaking and allows you to plant almost straight away, but you do need a fair bit of compost...also if you have bindweed and and couch grass it will still come through for a few years probably, but it will be weaker and easier to dig out.Remember to have a good layer of cardboard and wet it first , google it and you will find videos.
I personally before I knew about no dig, dug out tbe bind weed and couch grass over a few years - it was very hard work but I have virtually none now on the plot in most areas.