Mel sounds like you’re on the right track. Yes test ads are good. You can just use a pic of another home and not a factory stock photo.
All sounds good except I would caution you on buying a park with only 3 occupied lots. You’re going to be negative on cash flow likely for a while and buying, bringing in, setting up and selling is a great way to create a ton of value but it is capital intense and time consuming. Most people underestimate that process. It creates the most value but is also the hardest to do.
I alway recommend new investors find a light value add deal that has in place cash flow and a clear path to stabilization with maybe some infill but not heavily weighted on it.
Doing a very heavy lift for your first deal is riskier but also holds you up from doing more deals as it will take you years to fill that up which will take a lot of your time that could be focused on more deals. Not saying you shouldnt buy it but consider the value of your time and your goals and see if taking on a heavy lift gets you there.
My profile has some great resources for MHP investors. Hope this was helpful. Good luck with it.