Series of answers to a similar or same question have all be useful. Sure you can add them up yourself, or create a schedule that can monitor the length of each line and total them for you. But why? It is a one time use for a specific moment. If I select a series of lines that are connected (and are not in a straight line. The properties calculates area, not length.
Most disappointing response: Forcing a general user to create in Dynamo is not helpful and is frustrating. I, for one, am not a programmer and the process of using Dynamo is a deep black hole. . . at best.
There is no reason that I can think of that a simple selection of a series of connected lines cannot provide a total length in the properties.
