Trip itinerary with contacts - tell someone! 
In many cases a compass is useless without a map and knowing how to use it (setting declination, shoot a bearing and know how to do a map resection) that and GPS. Along with a knife, string to build shelter (paracord) and two sources for fire (lighter and waterproof hurricane matches), obviously sufficient water for the hike but bring purification tabs (or filtration kit) as well. All available at MEC, Canadian Tire, anywhere.
Never go trekking without sufficient kit to survive the night, if the weather is fine it may mean what's in your pockets - or it may require a full pack. Go with a fully charged phone and know the coverage area, reception is line-of-sight.
You might get away with it 99 percent of the time but every now and then nature can be completely unforgiving of ignorance and complacency.