This can feel pretty daunting, but the wonderful thing about cooking is that its difficulty almost always scales with what you actually want.
If you have little foundational knowledge about nutrition and what a home-cooked meal actually, like, looks like, I would recommend taking a bit of a hybrid approach: pre-made meals from a service like Freshly, Factor, or Sunbasket, and home-cooking from scratch. Think of this like training wheels.
Freshly, Factor, and other companies like them offer really high-quality, healthy, tasty meals with fully accounted for nutritional and caloric details. If you did a 7 or 14 meal-weekly delivery, you could have at least one guaranteed meal per day that would be something you could study and easily replicate yourself.
Now, as for actual cooking:
Identify a few foods that you typically gravitate to. I don't mean something as broad as "japanese" or "mexican," but more specific, like "ramen" or "quesadillas." Believe it or not, you can make very healthy versions of both of those foods - you just wouldn't want to eat them every day.
Once you identify the foods that you love, you can start to plan what your week will look like. If you want to have, say, chicken with potatoes and some greens for dinner every night for a week, you could do the following:
- Make sure you have at least one cooking sheet like this
- Get some oven mitts
- Get a sharp cooking knife (you don't need to spend more than 20 bucks on this)
- Get a multipack of meal-size tupperware that seals tightly, like this
- Go to the grocery store and buy cold-pressed extra-virgin olive oil (seriously, don't cheap out on your cooking fats, it affects literally everything and can make you hate cooking if you buy cheap shit) sea salt, black pepper, umami seasoning, oregano flakes, and your favorite kind of hot-pepper like cayenne or red pepper flakes
You can buy a 5-pound pack of chicken thighs for between $8 and $17 bucks, depending on where you live. This will make 7 dinner's worth of chicken.
Buy your favorite kind of greens, whether its broccoli, asparagus, kale, etc.
Buy a bag of russet potatoes. Don't peel them!
Buy some parchment paper. Put a piece of it on the baking sheet so it covers the surface. Pre-heat your oven to 375 degrees.
Heat a skillet on your stovetop on medium heat, pour a little olive oil in, and wait until the oil starts to crackle a little bit. Put the chicken thighs a few at a time on the hot skillet and get them a little brown - we're talking two minutes either side. Do this for all the chicken thighs while the oven pre-heats.
Once the oven is fully heated, put the chicken thighs on the parchment paper on the baking sheet, lightly drizzle them with olive oil, and sprinkle some salt, pepper, and umami seasoning on them. Cook for 40 minutes at 375.
While this is happening, prep a second cooking sheet with potatoes and greens. Cut the potatoes into quarters, and mix them up with the broccoli or asparagus on another cooking sheet, also on parchment paper. Season them with olive oil salt, pepper, and whatever else you're feeling, and wait until the chicken is done.
Once it is, put the potatoes and broccoli in the hot oven and cook for 30 minutes at the same heat.
Let all of this food cool on the stove - do NOT put it in your fridge while it's hot - and then portion them out in the tupperware you bought. Eat that shit all week.
For breakfast, you're on your own. I've never mastered anything past protein bars and eggs, but that's a willpower thing.