The Saturday night evening events will be happening at the Pavilion in Victoria Park.
Any bus from the university, heading towards Kitchener, will take you to the Charles Street Bus Terminal. To get to the Pavilion from there, head towards Joseph street (away from Charles Street). You will see a clock tower in Victoria Park. Head left towards David Street. Follow David to Schneider, go right. The Pavilion is the large building by the parking lot.
Follow the map above. There is free parking at the venue.
You can get to the Pavilion by trail. It is a bit of a trip. Follow the pink trail from the UW map until it ends at Erb/Caroline (Bridgeport ends and turns into Caroline). Follow Caroline until you find the trail on your right (near construction). Follow it all the way to Victoria street. It does a little jog, and if you cross the street at the lights and keep going the same direction, the trail will be on your left. You will cross a bridge, and some train tracks. The destination is on your left, through a parking lot and by a playground.