if a person has a dispute with an manager of a company, does he sue the owner of the company or the manager personally ?

Is the RV Park an independent legal entity, like a corporation or an llc?   Is the management company? If so, those entities can be sued.  If, however, they are sole proprietorships, they have no separate legal existence, and their owners are personally laible for any business obligation.  Even if the RV Park and management company are both corporations, however, you can still be personally liable depending on the dispute.  You would not, as a general rule, be persoanlly liable for either corporation's contracts, for example, but would be personally laible for your own torts.  For example, if you, while driving a van owned by the corporation in the course of your employment, get into an accident due to your negligence, you can be personally laible as well as the corporation being liable.