You could front the down payment as well as monthly payments to the seller, then charge interest on them.

Each property has two savings accounts - security deposit & reserves, and one checking - mortgage payments and utilities 

the rest of the loan payment right now is coming back to you eventually. 

When it comes to managing your mortgage, most homeowners are familiar with refinancing as a way to lower monthly payments or take advantage of better interest rates.

Do you need to refinance quickly to avoid a balloon payment or other financial pressure?

You have to borrow your equity and then make payments on it.

I'm very new to investing and weighing which options would benefit me the most.Option 1:  Use the cash as down payment on another primary residence and rent out the current.

I am currently in the planning phase of my real estate investment journey and had a few questions I’d like to ask someone more experienced.Would it be smarter to focus on paying down my own mortgage and then use a HELOC as a down payment for my first investment property, or should I simply use my savings for the down payment instead?

If you don't want that, I would sell it or put it into storage (which may not be financially feasible), but long-term renters are hard on furniture that is not theirs. 

@Timothy Frazier Yes, the only reason to use HML as a down payment is if the property is "mostly turnkey" AND you don't have the funds to renovate AND you have strong CMA comps from a real estate agent that supports that the fact that you are buying a property that is under valued AND your renovations would push that so that you could refinance.