ill help :)
ok! so if it says to do the skate park rules, it already says some of them. It already gave you an example so, heres one for must:
"You must take turns on the ramps"
and for must not:
"You must not use the skate park after 9 p.m."
like that!
exactly the same for the chores, except replace must/must not with i have to/i dont have to.
and for the last, make up some rules you would see in a library and use the must/must not terms while writing it.
Hope this helps :)