Blender - How can size the model with the "black line"

0:12 video how can get the black line to resize the model to star?

Have you tried pressing S, on your keyboard?

oh tysm but its not going to be star just resize

Are you in the Wireframe mode & have you selected “every other” face?

im in edit mode, i dont have wireframe

You need to click on every other vertices, also weren’t you supposed to have less vertices?