Cooking. Since no one else has really mentioned it.

The key to vegan cooking is umami. It's the 'savory' taste in meat, and you can find it in vegetables if you know where to look.

Onion, garlic, soy sauce, and mushrooms are the big ones. Shiitake are much better than white. Seaweed is also good. To a lesser extent, tomatoes, potatoes, and spinach.

I'm not vegan, but I don't eat much meat. I prefer to modify meat recipes, rather than seek out vegan recipes. There are a lot more non-vegan recipes out there. I recommend researching umami.

Eggplant and tofu sub for meat well. I actually like tofu, but I know many people don't. There are a lot of ways to prepare it, and you can do a much better job than most restaurants and processed stuff. Don't recommend Tofurkey brand anything; nasty.

Tempeh. If you can find it, get it. Great stuff. Makes great sandwiches.

Nutritional Yeast (nooch). If you can find it, get it. Best vegan 'cheesy' taste. You can sprinkle it on anything – soups, stews, popcorn. I'm fond of silken tofu with nooch, as a scrambled egg substitute.

Here's a vegan 'chicken' flavouring I really like. It's basically just nooch, garlic, and onion powder. But it's a good recipe. You can keep a big jar of it around to put in stuff, or make broth with.

Speaking of broth, learn to make a good vegetable broth. It's easy, and a good veggie broth will be better than even a meat broth from a can or cube.

I definitely recommend Koridofu. Ground beef substitute. It was created by Buddhist monks a millenia ago. Just freeze a block of tofu, thaw, wash and squeeze out the yellow water (tofu flavour you don't want), and cook with oil and umami flavourings like diced shiitake and garlic. The flavour is light, but the texture is surprisingly like ground beef (the ice crystals break it up in a special way). Great for chili, taco seasoning, etc. I eat it by itself with quinoa, with chili sauce and Sriracha.

I also highly recommend nut cheese. It's real, cultured, probiotic, tastes great, and IMO fun to make. I don't recommend any 'vegan cheese' in supermarkets (unless it's specifically nut cheese). That stuff is all nasteh.

I generally prefer nooch-based flavouring to sub chicken, and shiitake-based to sub beef. You're not going to replace them, but these complement best I think.

Finally, Thug Kitchen: some of the best vegan recipes out there.

As others said, watch your vitamins. Calcium deficiency will give you osteoporosis at 40. Vitamin D and Iron will make you anemic and tired all the time. B12 will do nothing for 10 years, and then you'll die a horrible, painful death. Not kidding. Take vitamins.