Do you have a balance on a mortgage? That will have to be paid off.
How about any personal liens - child support, etc. They have to be paid off, too.
You'll get a credit for the portion of any taxes you already paid that covered you past whatever settlement date you negotiate. For example, if your taxes cover you from Jan 1 through Dec 31 and you close on the sale of your home June 30, you are only responsible for the taxes through June 30 and you'll get reimbursed for the rest of the year. The same type of thing happens on water and sewer.
I'm not sure if Phila has any permits required when you sell your home. Many of the suburban municipalities require a Use and Occupancy permit when a property changes hands and most times, that includes an inspection for health and safety items. Typically, the seller pays for both the permit and the inspection. The repairs are usually the seller's responsibility too but most of these are negotiable.
Check with your listing agent for an estimate of closing costs to get an idea of how much you would walk away with from the closing table.