Drawing Shapes in Unity2D

I am a straight up beginner here, I'm wanting to be able to draw basic shapes like rectangles, circles, and triangles. Basically I want the starting point to be where my cursor is when I press down on mouseButton 0 and then I want it to be drawn when I lift up. Maybe I'm not searching for the correct things but I can't find a tutorial anywhere. If anyone can point me in the right direction that'd be great!