Norma, If you have onions you feel are too strong in flavor you can tame the bite by soaking the sliced onion in cold water for ten minutes or so, then drain and use. I have certain recipes, not always pizza, where I squeeze a couple of limes into the water for added flavor. I was out of limes one time and used vinegar and that worked quite well also. It does add an extra "something". When I make sliders I drizzle a bit of balsamic vinegar and water over the onions before I place the hamburger patties on top of the onions. Really gives them a added depth of flavor.
Don