I have a personal finance scenario where I'd like to know what other people would do if they were in my shoes.

In January 2021, I'll be about 18 months away from being completely debt-free (I'm currently renting for $1825/mo in Los Angeles) and I'm wondering if I should start investing at that point or if I should wait.

Once January hits, I'll have two loans left:
$45,000 on a car loan @ 6%
$24,000 personal loan @ 15%  
Minimum payments being $1125 and $437 respectively.

After all of my monthly expenses I'll have about $2500 per month to either throw towards debt or I can start saving for everything I need to buy a duplex or triplex that I'll househack in. From what I've gathered, I'll need to build an emergency fund that's at least 3 months of the mortgage and I'll have to save up the closing cost. I'll be using the VA Loan so I shouldn't have to worry about a downpayment. I'm estimating the monthly mortgage to be around $4000 per month so I'll be able to cover the full mortgage without a tenant if I combine my current rent payment plus the $2500. It'll leave me tight but once I have a tenant I'll be fine.

My question is Should I finish out the 20 months and be debt-free, going in with ~$4000 of discretionary income; pay off the 15% loan in 8 months (from January so Aug 2021), going in with ~$3000 of discretionary income, or is it wise to start now with ~$2500 of discretionary income.

TLDR Should I start investing now with $2500 per month, pay off a 15% APR loan in 8 months and invest with $3000 per month, or pay off a 15% and a 6% loan in 18 months and invest with $4000.