Last year I flew into KAGC and stayed for a week. Got a reasonably priced rental car from the FBO, and it's close enough to downtown (~20-25min drive if I remember correctly). Only issue is that if you get an Uber, they seem to have trouble finding the FBO since it's off the beaten path. Also, there's a nice little, out-of-place looking cemetery on the edge of the FBO (literally immediately adjacent to the ramp). That helps encourage good ADM IMHO!
I stayed at the Westin downtown on Penn Ave, it was only about a 15 minute walk to the baseball field, a walk I did multiple times. It's a a scenic walk, too, since you get a good view of the river(s), the downtown, and the stadium. There are also a number of hotels immediately next to the field if you're looking for something super close. There's a convenient stretch of bars and restaurants there, too. During my week there I think I might have visited every single one of them
Also, Pittsburgh ATC automatically just handed me clearance into the bravo airspace when I was on flight following both on arrival/departure. That made it easier and more direct to get to AGC coming from/departing to the west. I think it's a much quieter bravo from what I could tell.
Pittsburgh is a nice town, enjoy your stay!
PNC park:
The bridge offers a nice view of the city. I think it's the Warhol bridge.
This looks like an ominous photo w/the clouds, but it's actually very scenic with the rivers/hills.