Rice or pasta (like macaroni or shells, not long stuff like spaghetti) are both dead easy in the microwave.
Rice: 2 cups rice, 3 cups water, 15 minutes. 1 cup rice, 2 cups water, 10 minutes. Times may vary, these work on every microwave I've ever used - 1,000-1,100 watts. if you want to be sure it doesn't burn add a little more water. If the rice is watery, microwave a couple more minutes.
I don't like rice cookers, because they only do one thing and take up space - I don't like single use gadgets. Once you get this down it works every time and is no harder than a cooker.
Pasta: 7-8 ounces (I buy seven ounce bags, the Mexican stuff because it's pre-measured and cheaper) and water until it's covered by about half an inch/a centimeter or two - err on having too much water, you can drain it. I've never gotten around to measuring how much water I use. Ten minutes for fully cooked. Eight or nine to get al dente.
Salads:
Aldi sells these salad kits that are chopped vegetables, just enough dressing, something crunchy, and something flavorful. They are about 500-700 calories for the whole thing and will keep you full forever. The southwest one is amazing, unless you don't like cilantro.