Nobody is born with an intuitive understanding of how electricity works. Search "how electricity works" for pages and pages of basic information.
As far as wiring diagrams, they usually have symbols that represent a connection between two wires, a symbol for a plug-type connector, symbols for different components, a symbol for a "ground", etc.
The diagram itself probably won't explain these symbols since they are universally accepted, but a book for beginners on electrical wiring will.
The diagram will note the color of the wire with a couple letters, like " B " may mean "black" and B/W may mean "Black with a White stripe" . A 'legend' somewhere on the wiring diagram usually shows what abbreviations are used for what colors.
Check the resources for a manual and diagram for your bike.. good luck.