I recently sold a home and have an extra 20k in the bank should I pay the credit cards off, or use the 20 k to invest into properties?

Maybe @David Krulac and @Chris K. might want to give you some input.The Tax Claim Bureau (TCB) does have an obligation to notify lien holders; but that does not guarantee it happened.I would try to identify the amount of the HOA lien that this particular house had accrued; if it isn't so high it might be less expensive to pay it rather than fight.You are not entitled to any rent until you receive the deed.

The opportunity value at 10% return on $180 K is $1500/month.

@Alexa K.

Be careful on borrowing from your 401(k). 

My primary home has gained its value more than 500 K since my purchase.

Two things I find interesting here, one is the caveats with using Kiwisaver (similar to 401(k) plan in US) for first home buying, the other is the skyrocketing Auckland property market.

I currently have no real savings outside of my company's 401(K) and only a small amount of liquid stocks and cryptocurrency that I could sell.One of the private equity firms founders suggested flipping a couple multi-family or single-family homes in order to pay off my debts and build a war chest to be used as a down payment on a rental property (I thought this sounds like a good idea). 

@Dmitriy Fomichenko can share the requirements on this one, I don't have a SDIRA, only the solo k and can't remember what that one entails.The good: an excellent way to invest in real estate.

Looks pretty good but for a property that’s worth 130 k with Taxes at 5,000$ And Insurance 1500$ Yikes !