How can draw electrical and electronics circuits and diagrams?
I guess you’re meaning diagrams (symbolic ones) and not PCB Layout for copper etching.
The drawing toolbar is normally in the bottom pane. If it’s not there, just go to View → Toolbars and select Drawing. Explore the shapes, and don’t forget that the smart connectors can help to maintain consistent Glue Points.
By default there are just basic logic-circuit symbols in LibreOffice Draw. You can draw your own symbols and keep a copy in the Gallery or in a separate file. But many more symbols can be accessed by installing extensions.
See for example this question:
Whether Draw has stencils for Electrical engineering?
And here is another quite informative:
Where are the shapes in LibreOffice Draw?