In colloquial Japanese that would be three words: Kyou gakkou ikitakunai. The first word is "today" (unconjugated), second is "school" (unconjugated), and the third is the negative "wish" (volitional?) form of "to go" (iku > ikitai > ikitakunai). Subject (the speaker) is implied and neither the time nor the the topic/object needs to be explicitly tagged.