When I use my pen tool, it causes a thick block of color on both sides of line. HELP

[Marissa34926386azqz]

When I use my pen tool, it causes a thick block of color to show up on both sides of line. I have no fill selected. So I don't understand why it keeps doing it.  

[c.pfaffenbichler]

What are the Stroke Settings? 

Could you please post screenshots with the pertinent Panels (Toolbar, Layers, Stroke, Appearance, …) visible? 

[Marissa34926386azqz]

Thank you, I figured it out! Thank you so muchhhh!

[Shruthi Bharadwaj]

The thick block appears because you have an outline (stroke) set on your pen tool. Even though you don't see a fill color selected, the outline is still there.

[Jacob Bugge]

Marissa,

In addition to what c and Shruthi said, I believe you have a Stroke Weight far above the desired value.

For a redraw task like that I often use the lowest value in the dropdown (0.25 pt), along with a contrasting colour, preferably red as you have also chosen here.

[c.pfaffenbichler]

In some cases it can also be useful to create the line/s on a separate Layer and toggle the View Mode for only that Layer (by cmd-clicking its visibility icon in the Layers Panel).