Yes, going slow will help.
I started teaching my aunt's black and white paint gelding, Cash, barrel racing and pole bending last year because I'm in a club called Gymkhana and We walked and by the time it was over in early August last year (started in May so I started barrel racing and pole bending in March last year) he and I were doing Poles and Barrels at a trot. Haven't done them since last August, but I'm confident that Cash will do great this year and we might get up to a lope doing barrels and poles.
Patience is the main thing as well! haha walking is boring, but once you're able to do it at a trot you'll feel proud of yourself and your horse. :) best of luck to you!
A horse doesn't care how much you know until he knows how much you care.