Should I be taking supplements like vitamins or protein powder?
Well, it never hurts for anyone to take normal amounts of dietary supplements like vitamins and minerals. If you decide to eat no products from animals at all, you may want to take a sublingual B-12 supplement, and hemp seed or flax seed oil for omega 3's is good as well. Some people also take a Taurine pill or powder. Also, if you are a woman eating only 100% from the source, its good to take an iron supplement.
These are fine if it makes you feel more confident that you are getting all the minerals and vitamins you need, but all you really need to do is eat a good variety of foods close to the source, mixing plenty of beans, nuts, vegetables and grains.
As far as protein, you certainly don't need a supplement, but again, if it makes you happy, you can always make protein shakes using soy protein powder.