There is a hotel in the airport if that's your preference. But, IMHO the area right around the airport is super yucky. I would not want to stay in any of those airport hotels, just based on the area alone.
I'd rather stay in a nice center city hotel and then get to the airport via Septa Regional Rail.
PHL has Regional Rail commuter trains every 30 min all day long to/from Center City from the airport, costs about 7 dollars each way per person (kids ride free under the age of 12.) It's a 30 min ride from PHL to the Center City Stations (Suburban and Jefferson).
You can also take a cab, there's a flat rate of 32 dollars from center city to the airport and it's ~15 min ride unless it's rush hour.
Septa Airport line schedule (buy your ticket from a kiosk on the platform, otherwise there is an on-the-train surcharge of $2 more):
https://schedules.septa.org/current/AIR.pdf
Philly cab info:
https://www.phl.org/getting-around/taxis-and-limousines