Alright first off I am not a tax accountant. I used to work for a Big 4 accounting firm and my wife is a CPA. I do our taxes. In short, I have zero credibility whatsoever on this topic.
With that out of the way the short answer is no you do not give them a 1099 unless you’re paying them cash > $600 per annum on top of the free lot rent. Why? Because it’s on premises and exempt by the IRS: https://www.irs.gov/publications/p525/ar02.html. Search for lodging. If one wants to argue that lot rent is not lodging then it gets even fuzzier since this is basically a trade to let personal property sit on your business premises in exchange for part time (or volunteer?) property management services.
Generally you want this person to do as little as possible. You will see threads on here about managers stealing rent during collection. Make an effort to have the tenants pay you directly. There are some recent great threads on methods Park owners use to do this. In general you want them to be your eyes and ears for the Park, read meters / submeters, assist with meeting contractors for home rehabs and make ready.
For one time activities like selling a home where they have to field phone calls, put out bandit signs, show the home, get the paperwork in order, etc then there is a one time bonus of like $500 or $1,000 per home. Only really good managers can do this, and you may have to get creative to do it effectively for a small Park.