You will need to visit any property you are planning on buying to tour the property and take notes on the condition it is in, and if it is worth fixing up. Take notes of what you see on a nice legal pad, and try and estimate what it would cost to repair what problems you see. Note if the property falls into the category "light rehab" "rehab plus" or "full rehab"
Light Rehab would range from no repair skills (a cleanup, new paint, minor weekend repairs) to a project that requires light work from a handyman.
Rehab Plus projects would range from full work for a professional handyman to needing a licensed contractor.
Full Rehab projects would require the need of a licensed contractor, or multiple contractors.