First find a vacuum that will work for your kids. I have a small real vacuum that I can take the “stick” handle off of and the kids can hold onto the handle designed for carrying the vacuum up and down the stairs. If you can find a real vacuum your kids can use that is the best because it is “REAL” work. Alternately a toy vacuum will work.
Give the children a lesson on how to not run over toys or the cord, how to be gentle and not hit into furniture or the wall, how to empty the bag when full (it they are old enough), etc. Children’s Hearing Protection is a good idea too if you have some. Show them how to systematically cover the entire floor rather than just randomly vacuuming. Vacuuming helps develop focus, visual spatial recognition, and gross motor control among other things.
We found this awesome toy vacuum at the charity shop one day. It looked “real”, it actually picks up some lint and has a tiny collection bag that can be emptied periodically. When we first bought it, Mr Rockstar spent over an hour systematically vacuuming the entire house. Not only did he vacuum the house but he also picked up toys in each room before he vacuumed. After this I realized at 5 years old he was big enough to use the real vacuum since ours is on the small side. Now whenever it is time to vacuum the house all the kids want to help!