Develop fantastic writing skills as a newspaper reporter. You can have the most discriminating palate in the world, but you'll never make it as a food critic if you can't communicate well. If you are heading for school, major in journalism or English. Work on the university paper and try to write as many articles as you can on food and the arts. If you can't go to school full-time, try to take courses part-time and/or look into getting an internship at a local magazine or newspaper.
Create a portfolio of at least 40 written articles that you have written on food, wine, restaurants, chefs, food festivals, etc. If your plan is to become a food critic, then you must write all the time to have something to show to editors. Schedule writing one article a week until you build up a body of writing work. Apply to different newspapers and magazines regarding writing food columns. A big part of your life will be writing newspaper stories about all aspects of food. You will not start out as a food critic in most cases. You will start at the very bottom. There will be no job you won't do. When you do land a job at a newspaper, keep a travel bag packed at all times in your office or car. You might even get a job that doesn't focus on food at all, but it'll put your foot in the door and you can write about food on the side--in some cases, you'll inherit a food critic's position as a result.