Need help on how to continue investing in real estate

[Alejandro Patino]

Hello!This is my fist post so here goes nothing.I want to get into real estate investing.I already own one property in St. Louis for which I paid 39k cash (HUD property had help from my sister as I was living in California at the time).I rent it out for $750 a month and apart from taxes and insurance haven't had any major expenses as of yet.I've owned this property since summer of 2017 and it's been good to me :) I want to keep doing this and I've saved up some money around 60k and my father has agreed to let me barrow around 30k-35k if I need it.The value of my house in Missouri from what I can find online is about 54k now.all in all I would have around 90k cash looking to use for future investments.
 

   I work as a waiter(Houston)and before last year I was getting paid cash,so I only have w-2 for 2020.I didn’t make much much maybe 15k Bc of Covid(I did get  a cash job during covid and made around 10k).I’m at a point where I think I have enough cash to buy a duplex or maybe triplex,fourplex or whatever makes sense money wise.Home prices are relatively cheap in St. Louis since it’s  not the most glamorous city so I’m looking to buy there.I’ve found a few duplexes that are cheap and look like they can make a good cash flow(1200-1500 a month).They aren’t in super good areas but I’m  young and willing to take risks.

So what I’m really looking for is advice as to what I should do next.

:Should I continue to buy only in cash 

:Should I try to get a HELOC on my investment property(I've read this can be hard) to use for investing along with the money I have access to.

:Should I try to get financing thru the bank or credit union(would probably need a co-signer for this) this way I  could put maybe 20-25 percent down and keep investing since I would keep more of my own money.

Thanks to whoever took the time to read this.I would really appreciate any advice since I’m kinda lost a to what to do next.Did I miss anything? What am I doing wrong? Thanks 🙏