How many people use their model railroads for Operations

Greetings, I’ve made a few posts in the past showing my double dog-bone triple oval layout. Mostly I run continuously because the grand kids love it, but I did manage to place 9 different industries on the layout with spurs for drop off and pick up. My issue is that I get so confused when reading about car cards and waybills that it is quite discouraging. Can anyone offer a simple solution to start doing ops and how to set this up, and how to know where to pick up your next car and where to drop off the first car.