Hi Rachel! It depends on what you're in to! One usual must-see spot is Temple Square, which is the headquarters for the LDS church. It has some beautiful buildings, and grounds, and is located downtown just a few blocks from the conference hotel.
If you're into the arts, Salt Lake has the Utah Symphony, Utah Opera, Ballet West, and a slew of modern dance and theatre companies, and an art museum downtown. If you have the time/means, definitely try and get up into the mountains and see the scenery!
I'd like to explore SLC a little while I'm there. Any suggestions?