Overall, PA gun laws are similar to many states except they now have universal background checks on gun transfers except for (between) immediate family members.
Simply.... no loaded gun in vehicle unless you have a carry permit and then handgun only. No restrictions on what you have at home. No registration or foid cards for purchase. Background check required.
Carry permits are issued by the County. They are very easy to obtain if you qualify. This is for the state in general. Not sure about Philly.
No semi auto allowed for hunting (rifles and pistols). Okay with shotgun for small game.