You must want to do this from the beginning or you will be unhappy. If an offer is made, decide if you like the offer after you have thought it through and call. If you take too long, he will hire someone else. He has a business to run. Always make sure you understand the hours, duties, rate of pay, and perks if any.
Many employers provide water, sewer, electric, laundry and cable.
Some provide a phone hookup. If you select a campground look them up in a campground directory to see their rating. Look for a high rating that reflects good management usually, also look at its size. A large campground will have many RV workers usually with specific duties and shifts. Some rotate the shifts and days off.