"Out of state"  could be just across the border in Wisconsin or Indiana where the property taxes are much lower but you can still keep an eye on them. 

IMHO....tyvek and the other house wraps are applied as formalities rather than for performance.

From personal experience, and helping clients buy their properties (househack or as a rental), I highly recommend keeping an amount of reserves that is a little higher than what you may think to account for some of the unknowns.But also, this depends on the purchase price range of the property, the condition/need for repairs and/or capital expenditure repairs, tenant situations (carrying costs for if tenants aren’t paying or you need to go through a formal eviction or a cash for keys), unit turnovers, etc.

I'm not sure if you'd need a commercial business license (Formally known in Philly as a business privilege license) as a sole proprietorship.

An existing duplex will fall under a by-right use in CMX-1 (in almost all circumstances, especially if bordered by other residential use).The first thing I would do is go to http://property.phila.gov/ and look up the address and see its permit history (It may not have one.

Has a written formal business plan.

You need no formal education to get into RE, but there are tons of opportunities for those who do.  

I am physically disabled, was broke, and had only a year of formal education.

I don't have a formal  engagement letter with the accountant.  

Hi Edward, there is no formal REIA in Modesto.