Lots of excellent ideas. Most people have things in their fridge always, or pantry always, so those make the best quick and easy meals.
If you have bread and cheese, grilled cheese. If you have tortillas, quesadilla. If you have leftover rice, a quick fried rice. If you have kimchi or fermented other veg, throw those in. Eggs on top or stirred in. If you have canned broth, soup with mystery leftover bits. Leftover pasta, toss that in. Scramble eggs and mix them in with diced anything - frittata.
When cooking for 1, I always have frozen gyoza and a jar of kimchi - super quick, filling. There is often ravioli in my fridge.
As far as cooking, the hardest thing about proteins is you have to shop shortly in advance, or defrost the night before. But if you can manage that, any protein chopped with any veg and a quick dribble of oyster sauce, hoisin sauce, etc., makes a good stirfry.
Pasta a million ways. I love to open up a bunch of pickled veg (pickles, artichokes, roast peppers, olives) and toss them with cooked and cooled pasta. Use the marinades as your dressing. Toss in canned beans for protein. Or slice some salami in there.
Pasta, cooked, cooled, and tossed with diced cukes, scallions, and pb or miso mixed with a little oil, sugar, soy, hot sauce.
I used to make a lot of chopped veg, fried briefly in a saute pan with some croutons, a little bit of cheese, and put a sunny side egg on top.
I’m pretty sure that if you saute a little onion or garlic in oil, add some pureed tomato and cream, and simmer it for 10 min, that is tomato soup. Float crackers in it.
Breakfast for dinner is a winner here. Whipping up a batch of pancake batter and heating some frozen sausage links is so much less work than a savory dinner, with all the chopping. If you have frozen fruit, make a quick compote and call it healthy. We pick berries every summer and always have frozen fruit.
Good luck!