Welcome @Joshua Akpan!
You have come to the right place! Great first step to learning and investing.
As @Michael S. mentioned, check out BP's Ultimate Beginner's Guide, it helps to form a general foundation in the industry. Additionally listen to the BP Podcast and you will find yourself discussing REI in a much more professional manner very quickly. Also if you are a bookworm, check out the list of BP's 21 Best Real Estate Books, and start checking them off.
Philadelphia also has some very useful online tools to access public records.
I am closing on a triplex in South Philly at the end of the month, and love the strategy of investing in MFHs in/around the city. They key is making sure your numbers are solid. I am a Realtor in the city, and I look at the new multis that come on the market daily, and can tell you many of these properties are not good investments if you want to have a property that cash flows.
Best of luck!
-James