@Marcell Salmond Congratulation on your recent recent purchase! With you remaining 30k there may be a few paths that you could take.
Option #1: Either now or after closing I would recommend speaking with your loan officer regarding financing your next purchase. Due to record low interest rates that are still available, the cost to borrow money is currently very low. If you are able to get pre-approve for another mortgage, this may be a great opportunity to buy another multi-family property with good cashflow. Your 30k can be used as a down payment for you next purchase.
Option #2: Within Philadelphia there are a number of opportunities to invest in low-income rentals. In areas such as North Philadelphia and West Philadelphia. Low-income rentals come with some stress, but if you can handle it there is a lot of money to be made. Three bedroom homes rented out through section 8 go for $800-$1,200 a month. With the 30k, you can purchase the property with cash leaving you with no monthly mortgage payment for this property. This option is great for cashflow, because in 3 years you will recoup the 30k that you have invested.
@Marcell Salmond if you would like to discuss these options further, feel free to pm me.