Ok. Let's start the interrogation.
- Do you own this place or rent it (ie are you allowed to make changes, do you expect to be there long- or short-term etc)?
- How much time are you able/willing to devote to this?
- What's your preference - spend money to save time or spend time to save money?
- How soon do you want to see results?
- How old is DS and will he be helping?
- Are these beds in sunny or shady parts of the garden?
Depending on how you feel about all of the above, I would suggest
Tomatoes in pots or the raised bed - grow from seed or buy little plants, depending on your level of patience. Tomatoes need sun.
Courgettes, radishes, salad leaves are all easy from seed (although you need to be vigilant against slugs). Sweet corn is easy to grow but harder to get a decent crop. Carrots can be tricky, but may do well in the raised bed. Most herbs are easy to grow and can be bought cheaply in packs of mini-plants.
Do you like soft fruit? If so, raspberries or loganberries can be trained on wires along the fence or wall. Raspberries don't mind shade. The 99p Store has redcurrant and gooseberry plants.
If you like apples or pears, try a cordon tree by the fence or a minaret tree in a big pot.
If you want quick results with flowers, get one of the annual flower seed mixes that you just chuck onto the soil. Nigella, poppies, clarkia and nasturtiums are all easy-peasy from seed. Clematis will beautify even the mankiest garden fence.
Look for bargain plants in Lidl and the 99p Store. Raid the plant stall at school fetes and see if you have a local gardening society, as they often have plant sales in the spring where you can buy perennial plants which will go on from year to year.