your second amendment rights don't apply on private property. Please tell me how I'm wrong. I don't mind being wrong and learning new things at all, so go ahead. I won't bite.
US courts have ruled that the rights of private property owners diminish as you allow the public access to their private property. The specific case I have in mind pertains to shopping malls, but I can't remember the specific name of the case - i'll have to look it up.
Regarding private property and carrying firearms, it depends entirely on the state and each state is different. For example, in the state where I live, to legally prevent someone from carrying a firearm or other weapons on the property of your business, the business owner would have to install metal detectors/key card access/turnstiles/etc AND have a security officer or law enforcement present. If a person carrys a weapon on the property that has those security measures, they can be arrested for carrying a weapon. If the business does not have those methods present, they can not legally prohibit the carrying of firearms or any other weapons, nor have someone arrested for carrying a weapon. The business can post a "no weapons" sign, but it does not have the force of law. However, if you are discovered carrying a weapon, you can be asked to leave. If you refuse to leave, you can be subject to being legally trespassed (barred in the future) from the business. That is legally trespassing for refusing the leave, not for carrying a weapon.
Also, there are specific locations listed in my state's law where carrying a firearms is prohibited, and you are subject to arrest for carrying a weapon, but these are locations like municipal, county, state and Federal facilities, and the secure areas of airports.
As for private, non business property in my state, there are no laws prohibiting the carrying of weapons. If you invite someone into your home and they are carrying a weapon, you can ask them to leave, but you can't have them arrested for bringing a weapon into your house.
Federal law is different. With some exceptions, you can be fined or jailed for carrying a weapon into a Federal facility. But, that is Federal only, and does not apply to private businesses.
Not sure why we would talk about Washington State Law when there is no Disney resort there?
One of the persons posting in this forum made a blanket statement about 2nd Amendment rights not applying on private property. Since it was a blanket statement, examples that show that is not the case from different locations are relevant.