Hello Aeden,
welcome to the forum!
I'm glad you came here asking for advice, as it can be difficult to understand what you have to do on your own at the beginning.
We have a Wiki dedicated to veganism and philosophy, and a section to helping people go vegan.
Yes, after seeing your link it does indeed seem pretty unhelpful, and there's also harmful advice such as 'don't worry about the nutrients' - which just sets you up for failure.
When switching to a vegan diet, a mostly whole foods one is recommended, which is simply healthier (whole foods = more nutrient dense, less sugar and trans/saturated fats). You might want to pay attention to fiber intake at the beginning, as for some people switching from a diet with almost no fiber to a whole foods vegan diet with more than 60g of fiber a day can be problematic at first (if you have gut problems from the initial spike of fiber intake, try to slow into it with less fiber-rich foods first, such as mock meats, tofu and pasta as your main staples, until your gut bacteria adjusts and you can increase the amount of fibers you eat).
That said, legumes are the best staple meals to have (chickpeas, lentils, black beans, kidney beans, tofu, etc.). Then vegetables should also be had regularly, such as dark green leafy vegetables, carrots, sweet potatoes, broccoli, just to name some of the best. Whole grains, such as whole-wheat pasta and barley, can accompany legumes well in a meal. Nuts and seeds should also be a serving at least once a day, to make sure you get enough fats (peanut/almond butter, flax seeds, etc.). Fruits have quick diminishing returns in terms of what they provide, and keeping it limited to just 1-2 servings per day is probably best (prioritize berries).
You can also have processed mock meats here and there too, to help you stay vegan, but don't make it a habit for it to be your main staple (unless you need low-fiber foods at the beginning, and you're struggling to stay vegan, but as a long-term plan, legumes should definitely be prioritized over mock meats for protein sources).
Here you can find a
vegan diet plan for a week, whole-foods and healthy, with all the nutrients and costs written - although it's based on 2000 kcal/day only, but you can always simply increase portion sizes to fit your body building needs. We're getting around to writing a bodybuilding one soon.
Here you can find a growing list of healthy recipes:
wiki/index.php/Index_of_Recipes
In this section, instead, you can find general advice on a vegan diet:
wiki/index.php/Table_of_Contents#Culinary_advice
Then, of course, you need to supplement B-12 (cyanocobalamin) and D3.
Here you can find a page that addresses the nutrients of concern on a vegan diet:
wiki/index.php/Nutrients_of_Concern
(this is very useful as you begin, everything is science-based and plenty of references are given to show what the scientific consensus is)
We also have threads on the forum section to help you out, if you go in the vegan section of this forum (feel free to check the pinned ones).
If you have any more specific questions, do ask.
