Welcome @Dan
You have come to the right place! Great first step to learning and investing.
Check out BP's Ultimate Beginner's Guide, it helps to form a general foundation in the industry. Additionally, as @Mark Nolan mentioned, 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. I try and read at least 1 business book and 1 Real Estate book a month.
Philadelphia also has some very useful online tools to access public records.
I love the house hacking strategy, and think it can be easily applied in the city with a good lender. The key is making sure your numbers are solid. I live, work, and invest 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 desire a strong cash-flow investment. Reach out any time...
Best of luck!
-James