You also need to select a unique field from each of these layers which is how your results will be displayed. Calculating the shortest distance between two points is a commonly cited use for GIS. Distance from a point to a line is either the perpendicular or the closest vertex.
Start Learning for FREE Learn how to create a map tool that lets the user identify two points within a map and displays the real-world distance between those two points.
As you can only use two datasets calculate the distances between the first and. In the following image we choose these two points as starting and ending point for the analysis. It is quite probable that for some of our analysis we will need to include the distance between two given points measured in a straight line. In QGIS 32 you can use the distance matrix algorithm located in the vector analisysAnalysis tool window.