Define 'not getting' the canter.
Spurs are a quick fix. Over time, over usage will result in dead sides. I would get the horse used to a crop on the ground, so you can eventually carry one, but the bigger issue right now is your transitions.
A horse must be balanced and moving off your leg to get the transition. From walk or trot, both of these must be achieved. If not, your horse will run through your aids and rush and either rush/run into the transition (not balance) or not get the transition.
Work on transitions. Half halts, bending through circles. Using your seat and leg to keep the horse moving forwards.
Hope that helps:)