"Wamarekani wanaenda mkutanoni"
Translation:Americans go to a meeting
Mkutano is just "meeting", used as a subject or an object (eg. the meeting was good - I enjoyed the meeting)
Mkutanoni is a locative noun, used as a location in the sentence and generally equivalent to "to/from/at (a/the) meeting." After the verb kwenda, a locative noun is generally used to indicate the destination of movement. After the verb kutoka, a locative noun is generally used to indicate the origin of movement, etc.