First of all, buy a rice cooker. Rice is a miracle food. A rice cooker makes cooking rice easy, and you'll always have rice on-the-ready.

STIR FRY
Carrots, celery, chopped up. Whatever other crazy vegs you want. Your choice of meat/tofu. I fry up a bunch of tofu. Depending on how big your freezer is, you can prepare big batches and just spoon out some stir fry mix whenever you want stir fry. Oyster sauce (not too much!), soy sauce, cayenne/garlic/onion powders, a little sesame oil for the pan. I also like to put some kimchi in there. Once you actually have all the ingredients, the prep time is only like 10 minutes.

TACOS
Tacos also means you don't need to prepare that-taco-meat every time you want tacos. Refried beans, sprouts/lettuce, tomatoes/onions (or pico de gallo], cheese, sour cream, [cholula] hot sauce. This is a delicious taco, man, and it's ready with like 5 minutes prep time.
Quesadillas are also really easy - I'm going to tell you my secret recipe I've been eating several days weekly for like 3 years now. Tortilla. Put cheese and pepperoni on tortilla. Fold. Set iron on it for a few minutes. Bam - pizzadilla. You could also just microwave it a few mins, if you have a microwave.

MINI PIZZAS
Speaking of pizza, you can make like 4 mini pizzas at once with pita bread. Tomato sauce, cheese, pepperoni - or whatever you want, really. Put four of those in your oven and cook it for a few minutes @425.

SKETTIES
Pasta + that tomato sauce. I rarely eat spaghetti-type foods, but this is a great option for you.

TATERS
You can do a thousand things with potatos, but I didn't learn until a few years ago how easy it is to make home-made fries. You just gotta be careful 'cause this crap is hot. First you're going to need a dedicated frying pot, just go to a second hand store. Put some vegetable oil in that pot. Get some kind of metal strainer utensil thing, to take the burning-hot fries out of the oil. Cut up some taters into fry-like-shapes, or get one of those fry cutter things. Heat up the oil. Put those fries in the oil slowly, and in a few mins, they'll become fried. Don't completely cover the pot, the water vapor needs to escape or you'll get nowhere. Take the fries out out with your strainer, into a huge bowl lined with paper towels. Sprinkle some salt on those guys. Put a top on that bowl and shake it around! Bam. Fries.

Another good use for pita bread is simply pita+hummus. Rip off a chunk of pita bread and dip it in hummus. I love garlic hummus. Pita and tortillas are great alternatives to bread. The only thing I really use bread for is tuna sandwiches and grilled cheese. Tuna sandwich being: bread, with a drained can of tuna mixed with salad dressing/miracle whip. Grilled cheese has a bunch of variations.
Pancakes are easy and delicious.
Eggs are very versatile. French toast is delicious, which is just bread dipped in beaten eggs and pan-cooked.

I started living alone a few years ago with my highest cooking skills being microwaves and mac n cheese. Now I can make stupid simple crap like this. I am the laziest person.

Buying a rice cooker is decent advice, though rice isn't hard to make in a pot (2:1 water to rice ratio, bring it to a boil, once it boils, turn it down to minimum heat, cover, and let cook for 40-50 minutes).

Stir-fries were a godsend to me when I first moved out and started cooking for myself. It's a very simple thing to make taste good. Make some rice, fry some chopped veggies, nuts, meat or meat alternatives (to save $$$, I would only use meat once or twice a week), splash some soy sauce on the veggies while they cook, then dump that shit on your plate, dump the rice on there, add some more soy sauce if you like and voila.

Curries are also a great way to make tasty stir-fries. Once your veggies/meat are almost done frying, pour in some coconut milk, a nice big glob of coconut oil, and scoop on some curry powder. Mix it around until the curry has a thick, creamy consistency (don't over-do it on the coconut milk). Again, dump that on some rice and you are good to go.

Like >>250 said, make a large batches of things and keep them in the freezer. A big pot of chili (black beans, kidney beans, tomato sauce/soup, chili powder, cayenne pepper, mushrooms, corn) which you then dish into single-serving size containers and put in the freezer. Quick, nutritious meals for when you don't have time to cook.

Having a slow cooker is nice. Once or twice a month I'll go to the butcher shop and see if there is some kind of pork, beef, or bison roast on sale. If there is, I'll pick one up, throw it in the crock pot with a can of cream of mushroom soup and some diced potatoe. After 4-6 hours, the roast will be cooked, so I pluck it out, slice it up and ladle some of the potato/mushroom/roast run-off gravy soup thing onto it. You can also make stew in the slow cooker really easily. Chopped potatoes, peas, sliced carrots, diced onion, leek, mushrooms, and a sliced chicken breast or two or some chunks of beef, add some water and some salt and pepper and you'll have a nice pot of stew in 3 hours or so.

For lunches to take to work/school, get sandwich or wrap stuff (deli meat, mayo/mustard/whatever spreads you like, whole grain bread or wraps, lettuce... You could also make a big pot of burrito fixin's (cook some ground beef, sliced peppers, chili powder) and then a serving or two of that into a container and take it to work with a wrap or two, some lettuce and a container of shredded cheese. Put together a burrito for yourself at work. Yummy.

For breakfast, I like to make oatmeal in a 50/50 water/almond milk mixture. A little honey on that.

You'll save money by buying your staple ingredients in bulk (beans, chickpeas, rice, quinoa, etc) and supplementing that with fresh veggies. Grocery shop with weekly meal plans in mind (what do I need for quick breakfasts before work? What do I need for lunch at work?) and make larger batches which you can then keep in the fridge and eat over 2-3 days or keep in individual servings in the freezer and eat over 2-3 weeks.

If there is a farmer's market near you, shop there for nice fresh veggies.

For snacks, I keep a big jar of local honey to have on toast, and popcorn which I make in an air popper and sprinkle with butter, salt, and nutritional yeast.