It needs lead abatement and certification before anyone can move in.

@Kenneth Liz3rd party costs will include things like the title company doing the closing, title search, lenders title insurance, outside closing attorneys, tax certificate, flood insurance certificate, deed recording fees, postal fees, notary, wire fees. 

What are skills/certificates/associations can I gain or acquire that will help me in this endeavour? 

You need your collateral, purchase funds and then the legal and administrative costs you will incur converting a "Certificate of Purchase" into a "Tax Sale Deed."

How long does one  have to wait in order to sell the tax certificate?

It looks like it only costs you $100.Here is the link: https://www.ohiosos.gov/businesses/filing-forms--fee-schedul...You will want to select "File Foreign For-Profit Corporation Application for License Online at Ohio Business Central- Form # 530A.Make sure you have all of your New York entity documents ready when you click the link because you usually have to upload them (Articles of Organization and Certificate of Good Standing).I hope this helps!  

Just to add, when you move out there may be more expenses that you are not considering such as: Rental license for each unit [$63/yr], Lead cert for each unit [Varies depending on #bedrooms in each unit]Fire alarm monitoring (if needed) [$4-$600/yr]Fire alarm cert (if needed) [$100-300/yr]Sprinkler/standpipe cert (if needed)Refuse Trash Bill [$500/yr] or private trash pickupElectric bill for shared areas (Assuming everything is separately metered)Water: Most older rowhomes do not have separate water meters.

Different certificates in maintenance and construction.

And therefore whatever I've learned about budgets during my certification period, I have lost, due to "if you don't use it, you lose it) so I can't help you on that. 

I have been reading, listening to some very basic information regarding tax lien certificates and tax deeds.