I get weird shapes when I extrude and scale a mesh I am currently doing the doughnut tutorial, part 6, from this link, and I am now supposed to model a plate. Unfortunately whenever I copy the instructions, I get these really weird shapes and my plate looks messed up. 

I extrude and scale it but it just doesn't come out right.


created the circle


extruded


scaled it
You are using Proportional Edit with the "random" falloff setting. To turn it off, click on the blue button in this menu and select "disable":



or press O while in Edit mode