A weekend of exploring the arts in Pittsburgh!
You could make your homebase an airbnb in Lawrenceville. You don't need to be downtown, but it would be helpful to be close to 28 so you can get to where you need to go quickly. All of the bridges in Pittsburgh mean sometimes it can get congested, and it's best to avoid having to pass through tunnels to get to where you need to go!
Day 1: Randyland and Street Art
Since you're basing yourself out of Lawrenceville, you'll have no trouble waking up late and finding somewhere tasty to eat brunch. From there, check out the self-walking tour of Jeremy Raymer's street art. http://www.jmraymer.com/ He has lots of murals around Lawrenceville, some easier to find than others.
After you've finished your walk around Lawrenceville, hope in the car and head to Randyland. This place is incredibly unique and although it spans just the corner of a block, you could spend hours here trying to look at everything unique that Randy has created. If you're lucky, you might see him hanging around!
Hungry? stop by Primanti's in the Strip District for a typical Pittsburgh sandwich. You'll find more murals on your walk down the busy streets.
Day 2: Time to head to the musuems in the city and the August Wilson center. If you're lucky, you'll be able to see a show at the August Wilson, but at the very least check out their art exhibitions! There are a few more museums to check out (Carnegie Museum of Art, Andy Warhol, and the Mattress Factory.
Hungry? Make a trip to Market Square and try one of the many restaurants that are on the second floor of buildings, allowing you to people watch into the square!
Day 3 - ready for a little drive? Drive an hour and a half south to Fallingwater, a famous home of Frank Llyod Wright.
You're already in the area, so visit one of the many trials of Ohiopyle. You can find everything from bike paths to waterfalls. The Laurel Highlands area of Southwestern PA is beautiful, but make sure you bring snacks for the road. With so many parks in the area, why waste time driving through towns to pick up food? This is an easy way to save some money on your trip too :).
Photos included only of Randyland.