art vandelay
Well, I would suggest starting with tofu, tempeh and seitan since they are high protein foods, and they are also similar to meat in texture, which might be important for you in the begining. From my experience, I remember that I started eating more nuts and nut butters, since they are also a great source of protein. And lastly (I will leave some space for other people to jump in to this convo) :D I would suggest eating more leafy greens, such as kale, spinach, swiss chard...