Partner with a friend to protect both interests, create an Operating Agreement, and focus on saving and preparing for the down payment and reserves.

People want a place to store their stuff AND park their vehicles.

Then I asked if I could just store some materials on the land. 

What we do need is funds in reserves for any capex expenses in at least the first year. 

Yep, it's doable assume you qualify. depends on FICO, DSCR 1.00+ and I'd plan for at least 6 months of reserves. 

I list it in airbnb and Furnished Finders, if they reserve from Airbnb all the instructions are given to them through Airbnb.

If you have a super high net worth or income, perhaps your reserves could be lower.

A Heloc can "Never" be used as a "liquid" or PITI reserve which is required to buy investment properties.

If mixed in with your deposits and reserve funds, you may accidentally spend money you shouldn't have.

I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23If a purchase, you also generally need reserves / savings to show you have 3-6 month payments of PITIA (principal / interest (mortgage payment), property taxes and insurance and HOA (if applicable).