Sometimes the really basic questions are the hardest to answer, not sure exactly what you are asking:
To draw a 2D line, I would choose the polyline tool from the toolbar, then click on the settings to access the pen color and style. Then draw. If this doesn't make sense to you, then click on the help button, find polyline and then click on the "Working in Tool Settings Dialog Boxes". That link explains the common features of working with AC "tools".
Please work through the interactive training guides, available via the help menu. Start with Essentials, the others are all good. Do not just watch the tutorial, open the related files and work though each action as they demonstrate them. Also, stop and dig deeper, look into the other tool options that may not have been used in that step, but you see as being available. I notice that the passive learners don't seem to get much out of the tutorials, but they are good - if you work it.
Snap
PS BTW, please go to the profile area and create a signature that describes your AC versions and the operating system. This is what you see at the bottom of my post.
