Everything is possible. If by laptop drawing you mean you only use a touch pad, I would recommend you to use a mouse instead.
I think instead of a straight line, you wanted to draw a smooth line. Is this correct? If so, I looked up something. Select the pencil tool or something else to draw lines, and tick the box that says something that looks like 'smooth stroke'. Now, to smoothen your lines, increase the 'weight' value by a few hundred or so. Doing so will make the cursor drag out the line you're drawing, and this line will find it's average path. As a result, your lines will be way smoother. Feel free to experiment with this as much as you'd like.
Happy drawing!