everyone is different!! i need easy stuff to cook and what my preferred meal to cook is will change based on what's in the kitchen at the time. hopefully my examples of what that looks like can make it easier to envision what you can do and what pantry staples you might want!
i only tend to cook by a recipe for special occassions or baking, most recipes i simply eyeball and adjust over time based on trial, error and what's on hand. so what helps me most is to keep certain reliable pantry staples in regular rotation and build meals around those.
in keeping with that the setup for this section will be an example of something that strikes me as a pantry staple specifically useful for vegan cooking (so i'm leaving out pasta, rice, oats and such which we can all agree are pantry staples for most people) followed by examples of the types of things i've thrown together with that ingredient

dry goods
TVP/soy curls. dehydrated. proteins. dehydrated proteins. i cannot overemphasize how valuable these are. i like adding chunkier tvp into quick soups with vegetables and/or 1/4 of a ramen block to make ch*cken noodle or ch*cken and veggie soup. when i'm in the mood for a meat sauce, i do that by letting the tvp soak in a liquid seasoning of choice (usually some arrangement of soy sauce, vinegar, cooking wine, liquid smoke and a little bit of chili oil or flake) until it's changed color and gotten to about... al dente pasta texture?? and then cooking it up until it approaches more of a ground b**f texture and folding it into the pasta and red sauce. it's so good. it;s so good. i'm a poser and have not used soy curls myself just yet. but you can do the same stuff with them they're just bigger, so they're good for like... philly cheese steaks, meaty stir fries and such, where TVP is better suited to take on the role of ground meat.
dry mushrooms
assorted legumes. literally you will get so much mileage out of beans and lentils. dried if you want to save money and canned if you want to save time! garbanzo beans are great roasted or cooked and mashed into a ch*cken, t*na or *gg style salad (these are pretty much the same process for any flavor with minor textural differences, different mix-ins and different seasoning). red lentils especially take on a really nice texture that goes well in red sauces and curries.
flax/hemp/chia seeds. this is how u get ur gotdamn. omegas. the 3 ones i think maybe the others too. u can make chia pudding out of just the seeds, some time, and ur choice of tasty liquid for them to soak in. hemp seeds take to savory stuff well, they're really nice on salads! flax and chia seeds are both excellent to throw into oatmeal or cereal.
seaweed. the like. big thick sheets you have to soak. like korean dashima, not nori sheets. it's good in miso soups, as well as if you're making a dashi-like stock or a base for a jigae or tteokbokki this is a must. i've also soaked these and cut up the seaweed for adding to chickpea t*na salad (and also used the soak water to cook the chickpeas in).

fridge stored stuff
unsweetened soy/oat milk. any other plant based milk is fine but i use these most often because they take the least water to produce. you can easily make buttermilk out of these for pancake recipes. you can microwave them with cocoa powder and a bit of syrup to make hot chocolate. you can put them in cereal, oatmeal, coffee, sauces, soups. i like to get the unsweetened so that if i can decide how much sugar i'm adding to any of the above, plus that way, if i need a glug or two of milk for mac and cheese sauce or tomato bisque it doesn't leave a sweet vanilla-y flavor in a dish that i want to keep savory.
better than bouillon. it's so good to be able to make a soup on short notice.

liquid seasonings
golden mountain sauce. this is a thai thing and it tastes amazing. it's a good sub for fish sauce but ever since finding out about it i use it to season all kinds of things, putting a little bit into any kind of TVP meat, putting it in soups, using it as dipping sauce for dumplings, seasoning tempeh bacon with it, and so on.
soy sauce/tamari
cooking wine
liquid smoke

nutritional yeast
black salt
seaweed again. kelp granules, dulse flakes, furikake

when your brain is not cooperating for cooking no matter how easy you make it and you need to order out, it's good to have go-to cheap options. depending on your area, local restaurants are likely to have vegan options/what can be changed to make something vegan written directly into the menu. for larger food chains, it's easy to google which ones near you have vegan options and what they might be! it helps me to have go-to items that i know will always be vegan or can be easily made so without too many subs.

examples of what your fast food options may look like:
the cheesy bean and rice burrito from the dollar menu, no sauce and no cheese. get some hot sauce or have smth on hand cause this will be dry.
the spicy potato soft taco, also from the dollar menu no sauce and no cheese, add beans if u want... fried potato is BACK
cinnatwists!! vegan right out the thing thats just a fried piece of fussili pasta with cinnamon on it babey
ppl like getting stuff 'fresco style' and modifying the crunchwrap and other menu items but. if im ordering food its bc i dont have the brain for much, and if it's from here it's bc i don't have any money at the moment. so i stick to these items with rare exceptions

bey*nd avocado tacos and epic bey*nd original mex burrito are solid, no mod options if u want some m*aty slurry in there
avocado veggie bowl is just rice black beans avocado lettuce and tomato in a bowl if ur wanting smth lighter
side of beans without cheese or side of rice. these are beans and rice, respectively
french fries are french fries if ur wanting french fries
these are my go-to options as they're the easy. cheap, minimal modifications, and when ordering with nonvegans there's something for everyone

if these chains are not near you. i am so sorry. i just wasted your time so bad. fuck. these are like the only two i order from im sorry i'm not gonna eat a burger bun with just lettuce tomato onion and ketchup when i can get beans, potato and avocado instead. if you're trying to find the options at a place you already like you can always search 'vegan options (chain name)(year number)' and you WILL find detailed lists that even account for recipe changes. if you cannot find any i will eat my hat because this is SEO candy so it's like half of what vegan news websites do i swear.

general rules when ordering food from unfamiliar restaurants:
for salads- scan description for croutons and cheese (remove) and dairy/mayo based dressing. vinaigrettes or balsamic will typically be vegan.
creamy sauces of any kind usually are made with milk, butter, sometimes eggs, unless stated otherwise.
dessert items will often but not always have egg or dairy in their batter. any kind of cream/merengue etc is dairy based unless stated.
sorbet will normally be vegan and if it's not... there's no reason for that. someone's a freak who doesn't believe in the potency of fruit
it's actually fairly easy to order a cheeseless vegetable pizza. most but not all crusts will be vegan so ask if unsure
if something is labelled as vegetarian but not vegan and you can't figure out why based on the description 9/10 chance it's stuffed with cheese
(if you need proof of this please look at the shroom burger from shake shack)
if you get mediterranean food you can eat falafel, hummus, baba ganoush, toum, and usually the bread too (look out for yogurt based condiments like tsatziki tho)
indian korma and masala is sometimes made with coconut milk rather than m*lk but you gotta check. thai curries are typically made with coconut milk
you can almost always eat french fries