It is exactly what it sounds like, buying a property that has an existing debt on it.

Determine what type of property you want to buy - What Zip code, what condition homes, price range, etc.Contact 3-4 realtors that helped buyer agent buy the type of homes you are looking to buy.Then go with the 1 realtor that you connected with the most.

I wouldn't buy existing.

It's also how I find deals to buy as an investor as well.

I wouldn't consider buying real estate if I didn't have $160K cash in hand.

You didn't buy the house to preserve it, but for it to produce income.

Here in Columbus Ohio, you can still find the positive cash flow (aka the 1% rule) and you get amazing appreciation in any real estate you buy.

for double closing you would need your funds to buy then sell it to end buyer at premium. there are transactional funding companies that can lend the cash for a fee.

This is not a one size fits all answer, but bad debt is non-asset based or depreciating assets - , credit cards, medical, buying dumb stuff.Good debt is debt used to make or grow your portfolio. 

but you will have appreciation and equity paydown, but so would any property you buy with financing.