I'm new to Inkscape and cannot figure out how to create a curve into a straight line. I've only been able to make a curve to curve and don't know how to edit the control points to make a straight line. Any assistance is welcome. Thanks.

Shift + L should do it, once you're in the Node tool. This way you can edit the nodes after the curve has been created.

To create a straight line with Pen tool just use clicks instead of click and drag.

Or there's a button on the Node tool control bar (11th from left). And you need to have both nodes selected first. You can do that by clicking once on the line between the nodes. (Sometimes there are several ways to do the same thing with Inkscape. But in some cases, there is only one way to do something. I guess that's par for the course, for computers though.)

There's another way to do it, as well. If you have node handles displayed (happens when you select the node), you can hover the mouse/pointer over the tiny circle on the end of the handle. It will turn red when the mouse is positioned properly. The hold Ctrl key and click. If you ever need to make a curve again, you can draw the handles back out from the node, by holding Shift key then click on the node and drag.

Also, don't miss the links and info in my forum signature, for some great instructional material