When I was in school, we were given sentences to label and diagram. We were taught questions to ask ourselves while doing them to help us through the process.
The slanted lines in the first collum are Adjectives and the other collum they are Adverbs.
Basically, from my understanding, adverbs describe the verb. While an adjective will describe the noun. The verb is the activity of the noun.
I actually kinda forgot about these. They had us to these all the time but with larger sentences. The diagrams can get long.
Do they still have kids do this today?
As for the noun possibly being an idea, I assume something like "The plan is to swim today." plan being a noun.