Spurs are for refinement of a cue. They are NEVER to be used for speed. They make it so you can give a quieter cue. You only have to lightly touch with a spur, whereas you have to press with more pressure with just your heel. They can feel the change in your heel position easier with them, and there's more reinforcement. You are always to ride with a stable leg, and ask with your calf before your spur. Unless you have a solid leg, they are not a good choice for you. They will make a horse dull.
I ride horses 100% of the time in spurs. Even my first ride, the colts get spurs. Doesn't mean I have to use them. I was not allowed spurs however until I was older and stable enough to use them.
As far as the type of spur, I was started with a ball point spur. Now rowels, just a little ball to mess with. I now use a small clover rowel spur, mainly. I have other pairs but those are my favorites. You could also try a mild bumper spur (Without rowels). Most of all though, I would talk to your instructor and see what they think of the idea.
Pssh.I didn't pick up the wrong lead
It's called a counter canter...
...A very advanced maneuver.