This is the 691st most frequent Russian word.
ближайшее
"Closest" or "nearest."
In this sentence, "ближайшее" is used as an adjective describing the noun "кафе," meaning the nearest one in terms of physical location.
Найди ближайшее кафе.
Find the nearest cafe.
Here, "ближайшее" functions as part of a phrase, referring to the closest upcoming time.
На ближайшее время у нас нет свободных столиков.
At the nearest time, we don't have free tables.
This usage of "ближайшее" describes the spatial or sequential proximity of an event relative to the listener.