I shouldn't assume Fumi that you are female and if you are, you have to be even more cautious about having strangers in your home.  

Hey Kenny no it's more out the money to work and if needed get personally involved right right now have 3 clients I helped raised 175k in 0% interest business funding with 12 months 0 apr and they want to get going in real estate and make modest returns not shooting for home runs 

Does anyone know anybody who funds mobile homes and/or abandoned parks with infrastructure already in place?

Jung,Welcome to the BP forum its a great time to start as mortgage rates fall and home prices still priced well in many states.

Even though you want the ADU to be an investment and not your primary home.

We've worked with local banks and been able to finance the three we own without any issues.I don't necessarily know if it's "beginner" investor friendly but you'll learn everything you need in the bootcamp which is the gold standardWe get loans with 3-7 year balloons and 25 year amortization typically

I'm struggling because the first 3 homes I bought were homerun off market deals 3-4 years ago w/ great cash flow and appreciation. 

Rent out your current home.

The latter means you can also do an inspection of the home and see how things are.

Research local rental demand, especially from military and university tenants, and consider balancing your portfolio with single-family and multi-family homes.