You will be told what vitamins to take, what your protein goals will be. I made lentil, pea and asparagus soup pre op and puréed it in the blender then froze it in two ounce portios. Ditto turkey breast, chicken. Bariwise makes wonderful high protein low calorie fat free powdered drinks you mix with water that are good for all phases, EAS make a low fat, low sugar high protein shake I still drink daily because they are yummy and 17 grams of protein (EAS Carbadvantage) Livestrong and Cornell university have samples of diet plans for each phase so you can get some general ideas, but it will be up to your sugeon what you eat and when. When they tell you to sip liquids, SIP! And when they say bites no bigger than a pencil eraser, they mean it! Chew, chew, chew.
I am 10 weeks post op, have had zero food intolerances zero vomiting, have lost 35 pounds. Really listen to your body because you WILL feel different when you eat. Your feeling of fullness will be different( or at least mine was, helped to realize fullness by eating slower, small bites ang chewing well)
Hope this is helpful.