dimension drawing

Can you put your dimensions on a drawing.

Sure. When you start LibreCad, left vertical bar has an icon A above a ruler. That is how I usually use, snaps to endpoints enabled.

Check out the user manual for more details:
   https://librecad.readthedocs.io/en/latest/ref/tools.html#dimension
and
   https://librecad.readthedocs.io/en/latest/guides/annotate.html