I don't have a car and I get around fine for the most part.

I recommend you live within the peninsula of Pittsburgh (downtown - strip - oakland - squirrel hill - bloomfield - shadyside), as that's where most busses run.

There is a major bus line from Downtown, through Bluff, then into Okaland, then Squirrel Hill / Shadyside. There's another smaller bus line going north of Downtown through the Strip into Bloomfield and Shadyside.

Oakland / Strip / Downtown are probably the best places to live if you don't want to rely on a car. Out of those three, you'll have the most grocery options in the Strip. There aren't as many grocery stores here as you'd get in a larger city (for example, Lower + Central Lawrenceville don't have any major grocery stores within walking distance).

A lot of people love Shadyside but it doesn't have as much mixed development that other neighborhoods have (like bloomfield, southside, the strip, etc). If you don't drive, mixed neighborhoods are much better as it's easier to navigate and you have more stores within walking distance. I would consider Shadyside more bikeable than walkable as stores are more spread out there. Compare Forbes Ave. and Murray Ave. intersection area (Squirrel hill - more walkable) to Center Ave. and Penn Ave. intersection area which is a more bikeable feel (big box stores like target aren't great for walkable neighborhoods due to their large parking lots, among other reasons).