.- If you're handy, recommend buying a property in the worst condition you can tolerate.

Keeping my eye on the worst houses in the best neighbors that need some reno that I can turn into STRs or LTRs.

Quote from @Enrique Toledo: I came across a really good seller financing deal and I would like to purchase it as my first deal but I don’t have enough money for the down payment.can I use a lender of some sort to give me money for the down payment?

This area and this house will attract some of the worst STR abusers you can find.  

It’s kind of like asking what’s the worst part about not being a real estate investor?

That sort of thing is typically negotiable.

Looking for some guidance on resources of how to begin analysis or how to build a business of this sort.

Verifying last 2 years of rental history and income extremely important to find the “best of the worst”.Make sure you understand the Class of properties you are looking at and the corresponding results to expect.Thank you @Michael Smythe this is very helpful! 

Landlords sorted by unit count in Philadelphia as of January 20th, 2025.Note: It doesn't reflect pure ownership, especially for corporate landlords.

Otherwise you have to plan for worst possible results.