At the church I go to, there is a 6-month-old baby boy that I keep entertained with puppets and playing airplane. There are not a lot of "activities" to do with a kid at that age. They are usually happy with just funny faces or tugging on your necklaces.
Kids 6+ can sometimes be a handful. My nephew is 6 years old and there are times he just will not behave when his parents aren't around or are not paying attention to him at that moment. My best advice I can give you is to get eye level... more