So in terms of vital nutrients and a basic diet, what are some essential veggies/crops a person with limited garden space could plant to maximize the efficiency of their garden?

If it matters, the area is PNW, very rainy/wet during the winter but it rarely snows. I'm looking to start cutting down on grocery costs and start eating healthier in general but I'm not sure which plants would be good to start with apart from lettuce and beets and potatoes, maybe kale, but what else? I'd like to have it so we could always be taking things from the garden no matter what time of the year it is, is there a crop rotation planner online or something?

Any good resources/sites you have would be greatly welcomed!