Not necessarily. The absorption efficiency of B12 by the body is really bad, and the amounts of B12 in these foods are usually too small and comprised of the even less absorbable cyanocobalamin instead of the more recommendable methylcobalamin.
If one wants to go vegan, supplements like
VEG1 should be part of the diet, especially to cover for days where the intake of certain micronutrients is not sufficiently covered by regular food.
OP, generally, a challenge with a vegan diet is that it requires you to be more informed and aware about what you eat to prevent health disadvantages. Not that carnivore diets don't require that as well, but Vegan diets are more complicated, especially if your daily schedule does not allow you to prepare all your meals by yourself. In this case, a vegetarian diet is more practical and safe, especially if you only care about the health aspect of a meat-free diet, and less about the ethical ones.
As a side note, eating meat is not necessarily a disadvantage for your health. Generally speaking, diversity is always a benefit if you take everything with appropriate moderation.
But the amount of meat that nutritionists recommend is so low that most people would almost consider the resulting diet to be semi-vegetarian.
