Welcome to the forum.
To expound a bit on what Cousin Ed
has said, park models can be either self-contained or not ..."self-contained" means that an RV has holding tanks where plumbing can be used without being connected while moving around or on the side of the road, etc.
Those that are not self-contained do not have holding tanks. They are meant to be hard-plumbed either in a permanent or a semi-permanent manner. In other words, they are intended to be directly connected to the sewer at the site. It's essentially a mini-mobile home ...no fresh water or sewage holding tanks.
The tip-off is --does it have a residential -style toilet? If it has a toilet similar to one you'd normally see in your stick house, then it's the most obvious sign that it won't have holding tanks and your particular park model is designed to be permanently or semi--permanently connected to sewer and water connections at the site (you can connect to water in the normal way an RV does, however).
Here's an example of a park model with a "normal" toilet --a "true" park model trailer typically will not have holding tanks but destination trailers or park trailers can have holding tanks:
1997 Golden Falcon park model -- from ad at RVTrader
--see #14 of 16 on the photo display and it's attached below. Notice the residential -style toilet? Do you have a similar toilet? If so, you in all likelihood will not have holding tanks are will be required to directly connect to the sewer at your site.