Using the Line Tool - multiple lines

Hello, I have just started using Illustrator for the first time. It's the latest version, updated and all preferences have been reset to default.

I am trying to create a simple shape by drawing several lines using the line segment tool. When I drew the first line I was hoping to be able to simply click the mouse again to start a new line at the anchor point of the first line and then repeat this several times to create a shape. But when I hold down the mouse to create a second line the first line rotates rather than creating a new second line segment.  Do I need to create all the line segments for the shapes individually or is there a way to quickly draw multiple lines the are joined together? Thanks.