What wording should I use in the hearing to best describe that I did not aware this is an issue as everyone have bounce house for parties thru out the year?
Do you mean; what should I write to let them know I was ignorant of the rules and somehow that should mean they cannot enforce them?
Nothing.
Your only argument I can see is that if others are allowed (not just that they have them but actually
allowed to have bounce houses), there is a precedent set by allowing others to violate the CC&Rs.
Trying to argue that you should be allowed to have the bounce house because others have had bounce houses (against the rules) and gotten away with it is not a valid defense. You may simply be the straw that broke the camel's back and they must make an example to prevent further disregard of the rules.
That would be a touchy situation to do that and not have it seen as selective enforcement that can be shown to show a prejudice against you for whatever reason.