(be careful with the shinny object syndrome) in the early stages it may be a good idea to try to connect with lenders to find out about their qualification requirements to make sure you are checking every box.. also connect with insurance companies, realtors, contractors and others in effort to build relationships and don’t hesite to go visit properties that you would feel comfortable in buying it. 

If the house is zoned as a single family, then it's a single family and not a 2 unit in the county's eyes.Yes, you will have difficulty getting a rental license for a 2nd unit or using the income for qualification for a refinance or even considering it as a 2 unit for a refinance down the road. 

If it's a larger organization, feel free to inquire about their different staff qualifications.2.

If it's a larger organization, feel free to inquire about their staff qualifications.2.

The answer to your question will depend on if you live in the house or not.If the property is a personal residence, there is potential ways to get full exemption if you live there for more than 2 years or partial exemption if you lived less than 2 years and the reason you are leaving is within one of the 'qualifications'

Some big news last month.Lenders can now count income from an accessory dwelling unit (ADU) toward your loan qualification, according to an announcement from the federal housing authority a few weeks ago. 

Fairly easy qualifications as far as credit score and down payment.

And when it comes time to screen your tenants be firm in your qualifications.  

Few thoughts:(1) Submit offers on more than 2-units - you can go up to 4 for a conventional and FHA - I have multiple clients that have done this (though you can ask your loan officer for specific qualifications)(2) For mortgages - you only usually need to occupy for one year and then can switch to a rental and then use that income for your next mortgage "Borrower must occupy, establish, and use the Property as Borrower’s principal residence within 60 days after the execution of this Security Instrument and must continue to occupy the Property as Borrower’s principal residence for at least one year after the date of occupancy, unless Lender otherwise agrees in writing, which consent will not be unreasonably withheld, or unless extenuating circumstances exist that are beyond Borrower’s control."

All fha and va are assumable, with qualification of the buyer.