Go to home depot plumbing department, ask any home depot stuff in that depertment, they will tell you how to do it and what things you need to buy. It depends on what toilet you buy. It you buy a completed toilet, it comes with all install things you need, like was ring and screws that used to fix the toilet into the floor.
Or you can search on homedepot.ca "toilet install", there are videos to show you how.