I'm 2 weeks into eating vegan only. I was a pretty light meat eater anyway so picking up a premade nuke in the micro spag bol made with mushroom instead of mince is not a big deal. I am the worst cook I know though so if I get through the, limited in comparison, premade things in the Supermarket then the test will become real I suspect. Milk was my main worry but I found Oat Unsweetened works great for me. Well, I haven't tried it with cereal yet but I don't see it being bad. Admittedly this vegan kick coincides with a diet but it's preparatory-wise exactly the same as I was before. Buy a thing I can nuke, toast some bread, eat. No change in buying or making for me to be Vegan. So far at least.
Going vegan really isn't that hard, as far as cooking for yourself goes. Most of the recipes I use are not vegan but I just substitute cow cream/milk with oat/coconut/soy cream or milk, butter with different oils or plant-based spreads (depending on what I'm doing) and meat with chickpeas, mushrooms, self-made seitan or some commercial meat alternative that I've found I like, and that's about it as far as the steps I need to go through to transform most recipes. Because the funny truth is, most recipes are already technically, like, 95% vegan and it's really just the meat and/or the cream (and eggs) that make it not vegan. So once you just learn to pick the vegan cream alternatives and find your favorites from how to replace meat (be that chickpeas or meat-like vegan substitutes), you can just keep doing what you were doing before turning vegan with the most effortless changes to recipes.
Eggs can often be left out completely without need of any replacement without there being much of a difference and if there absolutely has to be something egg-like for whatever reason, you can start to delve into different styles of replacing different types of egg-usage (tofu, black salt & aquafaba are things you'll hear a lot about, and surprisingly bananas, avocados & apples in baking).
It maybe gets a bit harder if there's cheese involved, because vegan cheeses (at least the mass market ones) are still lagging behind in the so-good-that-you-don't-really-miss-the-"real-deal" sense in terms of taste, texture and/or how they behave in certain situations (like how they melt on top of a pizza), but
1) human taste is adaptable (something might taste weird at first but if you find something you even half-like, you might end up liking it a bit more down the road if you keep using it). I had a hard time finding a cheese I like for pizzas, but nowadays there are a couple I've come to like decently much, even though first impressions weren't super-favourable
2) there are some mass market vegan cheeses that work perfectly fine in some situations (perhaps not eaten separately or with wine like artesan cheeses or on top of a bread as is, but could work when melted into a cheese-sauce) especially if fine-tuned with some tricks (seasonings can go a long way to hide the weird (after)taste that quite a few mass market vegan cheeses have for some reason)
3) you can get a lot of mileage from nutritional yeast + garlic powder (+ onion powder) + cumin powder + vinegar/lemon-juice combo, especially when talking about cheesy sauces & dips. Nutritional yeast can add a cheesy taste to stuff (though be aware there are differences between nutritional yeast products, so you might have to try out different brands/products to find the one you like the best), further enhanced by garlic, cumin and a bit of sourness from vinegars or lemon juice.
But yeah, especially nowadays it's not all that hard to just take non-vegan recipes that you like and make them vegan with 2-3 meat/dairy replacements/omissions and basically get the same/really similar, delicious end result. Or at least something you'll learn to appreciate, even if at first you miss something from your meaty, dairy-y days.
+ as much as I personally love seitan and a lot of commercial products that emulate meat products, it bears noting that not every meal absolutely HAS to have meat-like stuff in it. Introduce falafels into your life if you haven't already (go to some local middle eastern food joint to get a taste of more authentic falafel, some of the falafel you might get from big store chains or, like, a falafel burger at McDonalds are often pale/shitty imitations of the real deal), check out some delicious Indian recipes/places that use beans, (chick)peas and vegetables in ultra-tasty, spicy/well-seasoned sauces and just explore the world outside having meat (even substitutes) in and on everything on every meal everyday. Like, a slice of (fresh) bread with some (good) hummus/other seasoned spread can be a nearly religious experience without any need for salami/bacon (or their vegan substitutes) that some people seem to stick to everything they eat.