@breko Hey, H. First off, congratulations on making such a life-changing decision. I have been vegan seven years.
When I first started I used lots of meat alternatives to help with the transition but over time I have completely stopped eating them except for an occasional fake meat product here or there as an indulgence. I follow a whole food diet for the majority of what I eat, but sometimes I indulge in more processed foods (beer, chips, dark chocolate) when I have the urge.
I take a multivitamin every few days and a sublingual vegan B vitamin a few days a week as well. In the winter I add in a high % daily value D vitamin because seasonal affective disorder sucks.
I have had only one issue while being vegan for so long. There was about a month or so where I was extremely tired and my eyelid started twitching very regularly and my hands were shaky. I added in the daily B supplement and the issue went away in a few days.
I have never had an issue with iron even though most omnivores think it is hard to get (eat lots of leafy greens!) I donate blood every eight weeks and the nurses always comment on how above average my hemoglobin levels are.
Besides the one energy issue, all I have experienced since going vegan are its benefits: I have lots of energy, my digestive system is ridiculously regular, and all my blood and hormone levels are healthy.
Eat the rainbow and try to eat from all the vegan food groups and you should be good. Try a calorie/nutrient tracking app like My Fitness Pal to keep track of macros and micros if you want.
A typical day: breakfast: oatmeal, chia seeds, berries, banana, cashew milk
lunch: lentils/beans and tons of veggies, usually a stew or curry of some sort
dinner: MASSIVE vegetable stir fry with seitan/tofu/tempeh
snacks: apples, watermelon, fruit, or sprouted toast with nut butter