2-3 usually. 1 each for hot and cold water and possibly a third for hot water going to dishwasher.
Valves under the sink NO WORK HUH?
Under the kitchen sink.
There are many different kitchen designs.
Sink strainer nut broken or loose. Putty under sink strainer rotted away.
Water Jetting ,snaking depending on what the stoppage is
look under the kitchen sink if he is not there then yes :/
Try looking for them under the kitchen sink, they might be there.
plumber
check that valves are fully open
We can't do diagrams, and many are slightly different. Google it and you will see many common fittings.
One for the hot water, one for the cold.
under the sink waste plug hole