To add to previous comments re crop rotation:
Stick wth one family per bed per year for crops that you would plant two successions of -- roots like beetroot and carrot for example, cabbages where you can plant out winter cabbages as you take up the spring ones. I also plant leeks after my autumn onions are out of the ground in June too.
Potatoes you only have one crop of per year, so I plant something I can get a quick crop out of after first and second earlies (like more beetroot, dwarf french beans, more leeks, spinach, florence fennel, winter radishes, turnips) that will mean the ground is free for the planned rotation family in the spring. Main crops potatoes are out too late to plant much else that year, but I follow on with peas and beans the next year, so start making a trench to enrich the soil for runner beans in that area, so it is ready in the late spring.
Early peas/mange tout are followed by another sowing, and main crop peas get salady things after them
Some veg are in the ground for a very long time, such as purple sprouting broccoli and sprouts, so I keep those together, which helps with protecting them from butterflies and pigeons, and means I am not trying to work around them al the time. I keep short brassicas like cabbages, caulis and dwarf kale together in another bed/part of the same brassica bed, not dot them all about. This way once the shorter (in time and in height )brassicas are out, I can plant more that will crop later. Swede go with them too.
Parsnips are there from sowing in April until around now, so plant those in part of your roots bed where they will not be in the way later in the season. I keep them with carrots as then I can cover then whole bed against carrot fly (learned that the hard way)
I plant courgettes about two feet in front of my runner beans - both are there all summer and get planted at about the same time - and sweetcorn with other squashes.
Beds are rarely empty for long, and when they are, they are being got ready for the next crop the following spring.
I hope that is not too muddly to follow!!