What are the little bugs on my Yucca Plant?

could be aphids, try hosing off with water before using a pesticide

I think what you might be seeing is baby Boxelder bugs. They are not harmful. In fact, they’ll eat things like aphids off plants while they’re maturing. Aphids are white and tiny so it can’t be that. Maybe you could post a picture of your yucca or find the bugs on line and post that pic? Good luck to you!!