Pranks Please!!!! me and my friend need help(we are 15)?

ok so me and my friend E**** are going to my familys cottage down by indiana beach and my aunt uncle cousin gma gpa mom dad other aunt and uncle and me and my friend are going and we need some good CHEAP! pranks to pull on them and they have to be age appropiatte cuz my cuz is only 6 we are right on the lake too