An inverter converts DC to AC. In the case of a solar panel installation, an inverter is used to convert the DC voltage of the batteries (typically 12 V, but not always) to 120 V, 60 Hz AC.
To be comfortable in your AS and use all of your resources, I would consider purchasing an inverter that will create enough power to run your AS. So that means you'll need at least a 3300 W inverter (110 V * 30 A). You can find relatively inexpensive converters from Home Depot, such as Power Bright 12-Volt DC to AC 3500-Watt Power Inverter-PW3500-12 - The Home Depot
. For $315 your getting something that will probably suffice for the summer. There are different types of inverter technology with pure-sine being the most favored for permanent installations and where folks are concerned about electrical noise. This inexpensive inverter does not produce a pure sinewave, but it's close enough for most tasks.
The other consideration is that this inverter assumes the batteries that you are connecting to are 12 V, so you'll need to confirm this with the campground. If their batteries are running at 24, 36, or 48 V then the inverter you will need will be probably be more expensive.
These inverters are also not designed to be exposed outdoors, so you'll need to make sure the inverter is placed in safe environment (protected from rain). You'll also need an adapter to connect your 30 A AS cable to connect to this inverter as well.