Which ones?

Perhaps choose 'patio' varieties of your favourites, they purport to take up less room. Choose things you love to eat but can't necessarily buy easily or that taste so much better home grown. My own choices would probably be courgettes, tomatoes and beans and maybe chard or carrots but yours maybe different. I'm glad I don't have to choose how about vertical growing, could you incorporate that at all in or around a caravan.