This is helpful.

I am an accredited investor, looking to invest 50k to start since it’s my first one, and predominately interested in multifamily as my only previous experience is a rental I manage on Airbnb.

Both offered up to $40k, 12-14% rate which is higher but not bad for an unsecured personal loan. 

The only problem is that last part - no matter what.Every new investor needs a "deal killer" in their life.

Austin is not a great cash flow market currently, but has proven to have solid long-term appreciation.

Is it foolish to consider using the HELOC for the down payment?

(Assuming quality of service doesn’t decrease.)No matter how you look at it, that is a ton of money.

if so maybe it doesn't matter but most construction loans would have had to be refinanced twice by now 

Quote from @Brandon Foster: Hello Ryan,STR is do able in the north county area but there are a lot of rules and regulations.The city of Oceanside right now will not allow anything STR unless it’s west of pacific coast hwy.This is changing a lot too so you need to be aware of that in your plans.Carlsbad is super strict too but there are some condos that are still available to do STR in.Medium term rentals are as safer bet but way less profitable.

After all, it was just 48 hours—how much could it really matter?